Something like this happened so many times to me(maybe not very many, but it is so frustrating that it sticks for a long time, longer than some my big wins). Last year I was going to bet $40 on the film Parasite to win Best Picture in the Academy Awards, and at the last moment I changed my mind and bet on f**king Joker, film critics' favorite at the time. I lost my bet because Parasite won Best Picture. The bet was in BTC so I don't even want to think of how much I really lost, and how much I could win placing my bet on Parasite with 3.5 odds.
This has happened also to me on numerous occasions lol. And afterwards, you always get mad at yourself and say to yourself that you need to stick to your first idea.
The one I keep remembering was a 7 fold parlay I made with a freebet on snooker. I was doubting who I should take for the last match and offcourse the only bet that failed was that one. Could have given me a sweet 10 mBTC ...