We live at the receiving end of a massive propaganda blitz from our materialistic culture. Most people simply blow whichever direction the cultural winds fly, as is graphically seen in how their likings change so quickly according to the fashions.
In such a cultural scenario, a few people stick to their own ways of living, saying that they want to be true to themselves.
This sentiment is good, but Gita wisdom emphasizes, we need to first, know what the true self is: the soul. We are presently covered internally by our minds conditionings and externally by our cultures conceptions. To be true to our self means to act according to our nature as souls, and delight in loving Krishna. For that, we need to counter both the outer cultural and inner mental influences by placing ourselves in a spiritually conducive environment and cultivating a devotionally receptive mindset.
Otherwise, in the name of being true to oneself, we may well be holding on to outdated conventions that are as untrue to our true identity as are the current fashions. The conventions that we follow in the name of being true to ourselves may well be nothing more than the external influences that had affected our ancestors.
The real criterion for deciding what is true to oneself is not what is conventional, but what is spiritual, that is, conducive for our realization of our true self. Using this criterion, spiritually realized people, the Bhagavad-Gita (02.52) indicates, stay uninfluenced by what they are hearing now, what they have heard in the past and what they will hear in the future. They are fixed in their inner connection with Krishna and in all that helps them sustain and strengthen that connection.
That steadiness is the true standard of being true to oneself.