I took a math contest in grade 7 or 8 just to get out of class... I knew I'd probably do miserably. I did, sure enough, but I got a certificate of participation. My mom or my dad put it on the fridge, probably thinking I did better than I actually did.
That's the closest I came to ever participating in a contest!
Except science fairs... one in grad 8, one in grade 10. In the grade 10 one I actually got 4th place in my grade, and I had done it the night before. It was mediocre and slapdash, but a rare treat compared to the others (this was a real slacker school). This university professor who was one of the judges was very impressed with mine... it was about floods, I just made up a whole lot of BS and didn't do any research... I made a dike out of cardboard... which was actually really just a little cardboard box... it wsn't that physically attractive... well it was, but in a messy, pragmatic-rather-than-beautiful-experiment sort of way... I just made a half-assed town in a plastic bin with little trees from the $ store, houses made of milk cartons and such, and stuff like that... the principal later told me as I went up onto the stage to get my prisze (a pen) that the professor had apparently been talking about how great my project was. 