Being hard on ourselves, being critical about ourselves, giving ourselves minuses may come quite naturally for some people. That is why we need to deliberately and consciously cultivate this positive quality of rejoicing in some of the qualities: Metta, loving-kindness; Karuna, compassion; Mudita, sympathetic joy; and Upekkha, equanimity.
Sometimes I reflect that we all as human beings have the potentiality to become free. These qualities of freedom are within us. So meditation can be seen as a way of acknowledging this, realising this and allowing these factors of enlightenment to arise in us.