I at times have issues with low-hanging lights, too. Tonight I was in one of the bathrooms of a family member's house where there are heavy vanity light fixtures hanging above the mirror. There was a cockroach high up near the ceiling, which startled me and I didn't have a broom or anything of reach to swat at it.

Lke an idiot, I climbed onto the sink countertop and when I was bringing my weight up to stand up on the countertop, in the moment I forgot about the vanity fixtures and bonked my head into one of them; it kind of felt like a brick. Hoping it is indeed just a subconcussive impact. The fixture is set in place and doesn't swing (stationary object); it was a heavy material that appears to be stainless steel or crystal.