In any case, no one in the lower-end workplace has been particularly interested in what brains I do have, or (apparently) anyone else's around me. It's all about how you can fit into the local pattern, which is often suboptimal yet resistant to change. Meanwhile, everything interesting/challenging I might have liked to work on is already being worked on by someone else, who is probably doing a better job than I would have-- so the chances seem low of me making a useful contribution. To say nothing of barriers to entry constantly & furiously being erected.
The main danger to me with regard to the question in the title seems to be the realization that despite what I was told as a child, I am pretty obviously redundant and unnecessary. Not needed. The world has enough brainy people already. There is little for me to do but try to care for those in my immediate vicinity as best I can and wait out my time.