I have a thyroid problem that used to make me... "unstable". With very poor judgement when under stress. Unsurprisingly, I burned through a fairly high number of jobs.
I'm not so bad with this now we're treating it properly, but people still think of me as the crazy version. What's worse is that because the thyroid problems can interfere with memory formation I can't remember large lumps of the time when I was doing this stuff. I tend to default to apologising to people I've not seen in a while (the ones who will still talk to me) these days on the basis that I probably did something to upset them at some point in the past.