Lets all vent just a bit.
We all have things that annoy us when it comes to being a musician. Things we have to do that just suck. Things that make it difficult to do what you love, or maybe things that are hugely beneficial for your band but are really difficult or tedious to do. So tell me, what's your "thing" and why?
Mine is probably booking a tour as an independent band. You can book a bunch of dates but it's so hard to get in contact with all these venues, find bands in the area that are similar style, find venues that are decent, make sure the same staff member(s) you spoke to are going to be there when you actually go on tour 6 months from now, etc. It always works out for the most part, but just such a pain to do.
Everything that is not actual playing.