I used to feel that way—feeling happy but then reflecting afterward, thinking I shouldn't have indulged in it and that I should be focusing on doing something useful for society. Only now do I realize I may have been brainwashed by certain ideas, becoming a product of conditioning. Phrases like 'Happiness is shameful; suffering is noble.' or 'Endure the bitterness of life, and you'll rise above others.' What drove the people who said these words to speak them?
wanting to be successful and disciplined is what drove people to say that i would assume
honestly it depends on what you wre indulging yourself in but most of the time if it is not that harmful then nothing really is wrong in indulging yourself from time to time life should be lived in fun and enjoyment and not only suffering