The practice of letting go judgment, comparison and expectation in the teachings of yoga, is exactly the opposite of the worldly thinking, belief, values and practice, in the competitive world of various forms of intelligence, talents, sports, skills, business and professionalism, that is mostly result, success and achievement orientated, that is about the development/empowerment of personal, family, community, school, company and national pride, determining the sense of self-esteem, self-worth, satisfaction and meaningfulness, through constant judgment, comparison and expectation from oneself and others towards the qualities of names and forms in oneself, and between/among different individuals and groups.
There's neither right nor wrong, it's just different approach, mentality, understanding and goal towards exerting energy into performing certain actions/practices/trainings that would lead towards what different minds defined as the highest development, improvement, transition, achievement or purpose for oneself and/or for others, in this life existence.
In the worldly thinking and practice, in order to motivate and inspire oneself to work harder and be better, one should constantly comparing oneself with oneself in the past, as well as comparing with all the others, to have great expectation towards oneself to become better and better, to be better than oneself in the past and be able to stand out among the others, and there's no end to continuous growth, improvement and achievement. That is deriving from egoism as well as empowering egoism. While in yoga, one can still be constantly improving one's physical and mental performance without the need of judgment, comparison and expectation.
No doubt that the body and mind is subject to decay and deterioration, and will stop 'growing' and followed by gradual decaying process at certain point, however, the body and mind can be maintaining certain degrees of good health and fitness level up to certain extend through engaging in certain regular healthy routine of mental and physical training and maintenance in moderation. Either over-use or under-use is not good for anything.
That's why in the teaching and practice of yoga, there are certain physical and mental training that could help to maintain certain degrees of physical and mental health and fitness level, if being practiced regularly under the correct understanding and attitude, but there's no attachment or identification, judgment or comparison, desire of craving and aversion or expectation towards the impermanent condition of the physical body and the state of the mind, knowing that it's the nature of the body and mind for being impermanent, as well as deterioration/decaying is the inevitable truth of all kinds of selfless names and forms, no matter how much effort being put into the maintenance of this body and mind. There's no dissatisfaction, disappointment, unhappiness or painful sorrow when the body and mind are losing youth, strength and mobility, experiencing aging, decaying, weakening, illness, injury, pain, discomfort, and approaching towards old age, death or decomposition.
In the yoga practice, one is practicing non-judgment, non-comparison and non-expectation in one's yoga practice as well as in daily life affairs, actions, activities and relationships with everyone and everything, either from oneself towards oneself, or towards others and among all kinds of names and forms. Respecting the perceived reality in the present moment now, as it is, as it changes from moment to moment, not necessarily pleasant, agreeable or desirable, without attachment or identification towards one's efforts and actions, and the fruit of one's efforts and actions.
Those who are free from judgment, comparison and expectation towards oneself and others, can still be doing one's best while engaging in various types of 'healthy' competitions, that promotes good health and fitness for the body and mind, as well as promoting sportsmanship and friendship among the different diversities in the world through the engagement of various forms of 'healthy' competitions. It's not so much about 'winning', but the entire process of persevered training and constant improving, physically and mentally, as well as the importance of sportsmanship in any competitions.
'Unhealthy' competitions are those that emphasized on the result, where 'winning'/'victory'/'success'/'effort well paid off'/'fame' is the highest goal of the persevered training, that promotes personal/group/national identity pride, and the sense of superiority, satisfaction and meaningfulness, where the minds might have difficulty in accepting 'failure', and would generate disappointment or shamefulness in oneself, and generate jealousy, resentment and hatred towards others who perform better than oneself, who beaten oneself in any kinds of competitions, while being demotivated to keep training or keep improving, after experiencing 'not winning'/'losing'/'failing' for certain times.
Healthy competitions are those that are about sportsmanship, and constant improvement of certain physical and mental talents, skills, performances and abilities, of certain business/professional strategies and services, to be using those enhanced talents, skills, abilities, strategies and services that can contribute to the world in certain way.
Healthy minds participating in healthy competitions are able to accept failure/not winning/losing, and don't generate disappointment or shamefulness in oneself, and don't generate jealousy, resentment or hatred towards others who perform better than oneself, who beaten oneself in any kinds of competitions, while still be persevered in one's learning/practice/training to continuously keep improving and keep trying, until one's retirement from such competitions. And it's okay, if after trying one's best, one still never win any competitions until one's retirement. That is actually more important than the one who is the best in one particular moment, who beats all the other competitors, or who stands out among all the others at that particular moment. And all are impermanent. The all time winners of any particular physical or mental competitions, will also have to retire, or passed way one day, as the body and mind is subject to decay or deterioration, even among the strongest or smartest people.
While being free from judgment, comparison, or expectation, just do one's best, without attachment and identification, will allow the mind to be free from unnecessary tension/pressure that would be affecting the physical and mental performance, and allowing the mind to be in the moment during the entire process of persevered physical and/or mental practice/training/development/improvement, and/or while engaging in any forms of competitions in the competitive world, without being distracted by judgment, comparison or expectation.
The relaxed/tension-free body and mind while engaging in physical and/or mental yoga practices will allow the mind to be fully attentive on the practice, being aware of the impermanent ability and limitation in the present moment, without forcing the body and mind beyond its limitation, which can help to minimize the risk of injury, as well as allowing the body and mind to be absorbing the effects/benefits of the practice more efficiently, without any expectation, craving or aversion towards the ability and disability of the body and mind in the present moment, or towards the effect/benefit/result/fruit of the practice, allowing the effect/benefit/result/fruit of practice being what it is.
Everyone has a different condition of the body and state of the mind, and it's impermanent. What the body and mind can do or cannot do, can achieve or cannot achieve in this present moment, is impermanent, and might be different from all the others. There's nothing to be comparing and judging about. Especially the yoga teacher and the yoga students in the yoga practice. The yoga teachers cannot say, "I can do this, so can you." Or in certain yoga teachers training courses, all students of 'aspired yoga teachers' are required to be able to do certain yoga asana poses, in order to pass the examination, and be graduated and qualified as 'certified yoga teachers'. That's pure ignorance.
The mind that is aware of ignorance and egoism, that is free from ignorance and egoism, that realized selflessness, compassion and unconditional peace, doesn't even need to be able to perform any yoga asana poses/chanting and prayer or possessing any 'recognized yoga teacher certification' to be guiding others onto the path of yoga.
Inquire the truth of everything.