Most of the stupider things I did was to
not ask certain ladies out. Errors of omission. One woman, I pursued for years, then failed to notice when she was being specifically receptive. Another, I pursued intensively for 15 months, then didn't accept when the opportunity came up.
At one point, I went out with someone who turned out to be married. That's not too bad. The bad part was that I didn't stop completely once I found out what her marital status was.
That one, and the one I pursued for 15 months, I used to sit between in MACRO-32 class. Distracted the professor a lot.
THE stupidest things, I won't document. They're too... unfortunate.
I can speak of stupid things women have done on dates with me, such as ridicule my profession w/in 5 minutes of starting our first date. That's pretty bad. Oh, you want a second date? With whom? I was meeting these women via a matching service. I took to meeting them in a bookstore's associated Starbucks so that I could at least get a decent drink and some book shopping in after the date didn't go anywhere.
Most recently, I spent a lot of money and effort on a date with a woman who didn't even
remember, or who put it out of her mind fairly quickly. The more fool, me. I guess I shouldn't have bothered.