You just went up against one of your stronger enemies. You beat him, but not without getting your ass handed to you first. Not only do you have to fix up your costume yourself, but you better be pretty good with a needle and sutures. Go to the hospital? How are you going to explain all of your injuries? What if your fight with the super villain was televised? What if people put two and two together and realize that youre always going to the hospital right after your superhero persona gets beat up? You really cant take that chance and unless you have a confidant whos good with first aid (Seriously, not everyone has a former army doc for a butler. My butler majored in philosophy).