Indulgence usually means doing something which makes us really happy and doing it too much.
Abstinence, on the other hand, means restraining ourselves from doing that which makes us really happy.
These two are opposites, so how does one have both?
Simple!
Two opposite things can both exist, just not at same time.
So spend some time doing abstinence, then spend some time doing indulgence.
Its really the best of both worlds.
For example, being thirsty and not drinking water for some time. Then after a period of restraint, you drink a lot of water at once.
Same works with hunger.
If you are hungry for the whole day but not eating, then you eat a lot at once, its gonna feel really good.
Abstinence produces pleasure, and indulgence produces pleasure. However, in combination, they produce even more pleasure.
Life is all about opposites.
You are supposed to practice opposite things in your life in order to be more happy.
For example, if you play video games, you can spend two days not playing at all, and the next day playing a lot.
Abstinence alone or indulgence alone works too, but I figured if they both work good on their own, they will probably work even better together.
Together they work fine in case of eating, because you can practice indulgence in food without getting fat because you are also practicing abstinence.
Its magic, really.