Compassion is not a sentiment.
Compassion is not about pleasing all and everyone to make all and everyone feel happy, good, positive, and meaningful, or to take away the sense of unhappiness, badness, negativity, and meaninglessness from all and everyone.
Compassion is the selfless indiscriminate and unconditional power of manifestation, existence and function, and inter-supporting actions or activities, that enables all and everything to be existing and functioning as what all and everything are.
It is a selfless power of manifestation or existence and function that exist and function selflessly in all and everything and the surrounding environment that are selfless, impermanent, limited, conditional, and non-self, where all kinds of selfless names and forms are existing and functioning as what they are, selflessly, to be indiscriminately and unconditionally inter-supporting the selfless existence and function of all and everything to be existing and functioning as what all and everything are, momentarily in this space of the universe that doesn't belong to anyone or anything.
In the yoga class, the yoga teacher might or might not emphasize on bringing the awareness, or attention, or focus onto the centre of the heart (the position of the selfless organs of the heart and the lungs).
It is not so much about stimulating, or stabilizing, or energizing, or purifying, or opening the so called 'Heart Chakra', but it is for the minds to have a direct reflection or contemplation upon the selfless compassion that exists in all and everything, that enables all and everything to be existing and functioning as they are.
We all are existing, functioning, and living in this present moment NOW, is because of the power of selfless compassion that exists throughout the entire selfless physical body and in the surrounding living environment that provides the supportive selfless energy and many other selfless elements for all kinds of names and forms to be existing and functioning as it is.
If the heart and lungs are not selfless and are functioning under the absence of the selfless power of compassion, or if they are functioning under the idea of 'I' (the ego) and egoism, where they have the sense of 'I' and 'mine', self-esteem and self-worth, superiority/inferiority, deserving/undeserving, pride/shame, success/failure, selfishness, possessiveness, discrimination, desires, discontentment, anger, hatred, fear, insecurity, and greed, just as the corrupted minds of many human beings, where they have the egoistic impure tendency to interfere, invade, attack, intimidate, threaten, bully, conquer, and control, and to manipulate, oppress, influence, discipline, and punish all the other organs or systems in certain way or not in certain way, where they will want to hurt and damage and destroy all the other organs and systems that they dislike and disagree with, it will be exactly like what is happening in the world of human beings, where the many minds of the human beings are functioning/operating under the influence of the idea of 'I' (the ego) and egoism, under the influence of the veil of ignorance/impurities and restlessness, where there are so much unnecessary hurtful and damaging physical and mental activities happening everywhere in the world, starting from within the minds themselves, that extend to the surrounding environment, into the personal and community ties and connections, relationships, affairs, and interactions with all and everyone and everything, into the family and one's particular community as well as the other communities in the world of many diversities that doesn't belong to anyone or anything.
If the 'prideful', 'self-righteous', 'possessive', 'selfish', 'discriminating', 'easily be annoyed and offended', 'highly sensitive', 'attention and agreement seeking', 'full of desires of craving and aversion', or 'angry and aggressive' heart and lungs decided to stop functioning, not performing their respective duty and responsibility, or being discriminate towards certain organs or systems in the physical body, as they get upset and angry and hating towards the other organs or systems due to their desires of craving and aversion are not being gratified, or when things are not happening in the way that they desire, like, and agree with, or they want to covet and occupy the space of the other organs, it will be the end of life existence for the entire physical body.
Self destruction.
Such as the egoistic human beings that are hurting and destroying one another and the surrounding living environment that doesn't belong to anyone or anything, under the name of self-righteousness based on one's particular belief and under the excuse of survival, either consciously or unconsciously, wittingly or unwittingly, intentionally or unintentionally, directly or indirectly. - Self destruction.
Blaming the survival instinct? What survival instinct? Because of want to survive, oneself and/or one's particular community want and need to hurt and destroy the others? That is nothing to do with survival instinct, but merely ignorance and the by-products of ignorance, or mentally corrupted, or mentally unwell.
All and everyone MUST look after one another, and not like what is happening in NOW, in the world of human beings, where there are all kinds of selfishness, possessiveness, discrimination, violence, and cruelty, where the minds are being conditioned to profit oneself and one's particular family/community selfishly, as well as being discontented, ambitious, and greedy to be coveting, possessing, and hoarding unlimited natural resources/lands/space that don't belong to anyone or anything, for the survival and enjoyment of oneself and/or one's particular family and/or community.
If human beings don't look after one another but being discriminating and cruel towards one another, there is none, not any individual, not any community, can survive, in peace, not to say, to enjoy this or that, as there won't be a conducive surrounding living environment for survival or making a living, not to say, a pleasant enjoyable environment for additional pleasurable leisure enjoyments, but only full of fear, hatred, unrest, and violence everywhere.
It is never too late.
To (start) promote peace and harmony among all diversities, to look after one another and the surrounding living environment, indiscriminately and unconditionally.
To refrain from any ideas or activities that are promoting untruthfulness, lies, story telling, superstitions, myths, manipulation, mental and emotional dependency, ignorance, restlessness, the ego and egoism, pride, possessiveness, greed, selfishness, separateness, discrimination, exploitation, bullying, politicking, anger, hatred, or violence.
To start looking after one another, to extend a helping hand, to the ones in painful suffering, to the ones that are weak, young, old, sick, injured, disabled, less opportunity, or unfortunate, to the ones being exploited and bullied, to the ones being ill-treated, to the ones that in need of helps, to the ones that don't even know that they need help, and to the ones that don't know how to reach out for help, selflessly, indiscriminately, and, unconditionally.
And all that, has to starts from within oneself.
Help oneself, accept and love oneself as one is, be kind to oneself, and liberate oneself from ignorance, selflessly, indiscriminately, and unconditionally. Then, everything will be happening accordingly, even without any intention to help others or be kind to others, but all one's thinking and activities will be promoting peace and harmony in the world of diversities, that will be benefiting all and everyone and everything, selflessly, indiscriminately, and unconditionally, in one's life, in one's family, in one's relationships, in one's work place, in one's neighbourhood, and in the surrounding living environment.
Inquire the truth of everything.