Apologies for this being even more off topic, but I have a funny story along these lines. After I graduated college, I was ranked about #20 in the US in sabre fencing, and the choices then are essentially 'keep going and try to make the Olympic team", 5 people per weapon, or 'quit'. I had beaten 3 of the 5 Olympians that year ('88) in different major tournaments but I didn't really train super seriously (I was 21!) and I couldn't string together enough wins on the same day to be a genuine top 5 Olympic contender, plus there was a lot of dubious cheating etc at that point in the sport that would have been hard to overcome without truly transcendent talent. Plus of course there's no money in it.
So I quit, didn't look back, I had done it for 10 years. My brothers were both very good collegiate fencers and as the next year progressed, they started talking shit to me. So after a bit, I said 'fine, we can all enter the Garden State Games (the NJ state championship at that point) this summer, and we'll see.' I practiced just once beforehand, the first time I had picked up a weapon in a year, and I beat my youngest brother in the quarterfinals and the middle one in the final.
But what made me think of this was your post, because my mom was there and she felt bad for my brothers, because she knew I was not going to allow myself to lose to them. So my mom was actively cheering against me! I think there is a VHS record of this somewhere, I should get it transferred sometime.