I'm curious if / how other people out there challenge themselves as photographers. I like to give myself challenges once in a while, like only shooting in B&W one day, or only using a certain lens. Today I'm about to take my son to the museum for an astronomy presentation they're giving. I've decided I'm going to only take my 45 1.8 today and leave everything else at home. It will be my first time using the lens since buying it about a month and a half ago other than to make sure it wasn't broken during delivery. What kind of stuff do you guys do?