What do you usually do once your sim completes their aspiration?

I change aspirations as I go. I might keep in mind that I want to be a World-Famous Celebrity, but when I go out to a club I switch to Friend of the World. I pop over into Bodybuilder whenever I work out, visit the gym just to tick something off, and end up getting a few aspirations done on the way to the one I originally chose.

Since I do bits and pieces of most of the aspirations I don't finish them all, but if I decide to change directions, I've already got say, the first level of Collector finished, so it's easy to pick up and make it my main aspiration.