A happy mind or an unhappy mind, is not about whether the mind is feeling happy or unhappy most of the time, or all the time. A happy mind can be unhappy some of the time, and an unhappy mind can be happy some of the time. The mind is neither happy nor unhappy. It's merely some impermanent feelings and emotions arising and passing away. It's about whether there's attachment and identification arising in the mind attaching and identifying towards the impermanent feelings and emotions, and hence, swaying restlessly between feeling happy and unhappy under certain conditions, or the mind is being content and happy as it is, unconditionally, transcending the impermanent happy and unhappy feelings and emotions that ceaselessly arising and passing away.
The minds that are free from ignorance and egoism, that are not being conditioned or determined by the presence and absence of certain qualities of names and forms, or the perception/experience of something pleasant/unpleasant, desirable/undesirable, or agreeable/disagreeable, or the gratification/non-gratification of desires to be happy or unhappy, they are resting in the state of unconditional contentment, being content as they are and happy as it is, unconditionally, transcending all kinds of pleasant/unpleasant experiences, void of attachment and identification towards the impermanent modification of the mind, while respecting the selfless impermanent changes as they are.
It doesn't mean that these minds don't perceive anything as something pleasant/unpleasant, desirable/undesirable or agreeable/disagreeable, or wouldn't be having and/or expressing any understanding or emotion of like and dislike or agreement and disagreement, however, all kinds of reactions under different emotions that are impermanent, don't determine, influence, affect, disturb or change the state of the mind that is being content and happy as it is, unconditionally.Such minds can be perceiving and reacting towards certain ideas, behaviors or events, expressing agreement or disagreement towards certain ideas, behaviors or events, and there are different feelings and emotions arising and passing away in the mind, but, it doesn't mean that these minds are happy or unhappy minds, as there's no attachment, identification or association towards the impermanent modifications of the mind.
Healthy minds are capable of being peaceful and happy as they are, where they are not being determined by the presence and absence of interaction, attention, love, care, support, encouragement, acknowledgement, appreciation, agreement, praise, compliment, sympathy or empathy from others, to feel happy, love, good, positive and meaningful, or not. They don't need any others to keep checking on them, "How are you?", "Are you OK?", "Are you happy?", and so on.
These minds are peaceful and happy as they are, regardless of the different impermanent feelings and emotions arising and passing away in the mind, under any circumstances, conditions and situations, void of grasping, or attachment and identification, transcending the intellectual cognition towards rightfulness and wrongfulness, goodness and badness, happiness and unhappiness, agreement and disagreement, like and dislike, achievement and non-achievement, easiness and difficulty, success and failure, meaningfulness and meaninglessness, and etc.
These minds don't need to rely on any external influences of pleasant/desirable/agreeable experiences that give rise to the momentary sense of satisfaction and happiness, or rely on the momentary effect of certain physical exercises or positions, breathing control, mental control, sound vibrations, or drugs and intoxicants that induce momentary calmness, relaxation, unwind, contentment or happiness, for being peaceful and happy as they are, unconditionally.
There's awareness towards some impermanent happy or unhappy feelings and emotions arising and passing away, but there's no attachment or identification of "I am happy or unhappy." Neither there's desire of craving and aversion of "I want to be happy," or "I don't want to be unhappy."
Meanwhile, due to ignorance and egoism, the egoistic minds need to have specific 'happiness deserving' reasons/factors to feel happy and be happy, or will be unhappy being determined by specific 'unhappiness deserving' reasons/factors, being influenced and determined by the presence and absence of pleasant/unpleasant, desirable/undesirable, and agreeable/disagreeable experiences, relationships, interactions, events, places, environments, conditions and situations, swaying between the state of being happy and the state of being unhappy, restlessly.
There's attachment and identification towards the happy and unhappy feelings and emotions of "I am happy or unhappy." There's also desire of craving and aversion of "I want to be happy," and "I don't want to be unhappy."
The minds that are under the influence of ignorance and egoism, that couldn't go beyond the attachment, identification, desire of craving and aversion, comparison, judgment and expectation towards the presence and absence of certain qualities of names and forms to be the specific reasons to be happy or unhappy, can also realize this unconditional state of the mind that is "peaceful and happy as it is," upon the weakening, thinning out and annihilation of ignorance and egoism.