How do you balance your "short-term" and "long-term" happiness [see details]?

I don’t really know how to phrase what I mean, so here’s an example: on any given weeknight, I’m often low on energy and don’t really feel motivated to do much besides waste time on the internet. However, I know that if I give into this urge all the time, I will be very dissatisfied with my life, as it will feel meaningless and empty.

Does what you want in the short-term often conflict with what you want your life to be in the long-term? How often do you force yourself to do something you don’t really feel like doing for the sake of your long-term happiness?