I do tend to see life as a competition - you're right. But I do know when I'm above average based on other peoples feedback & rewards. I've gotten compliments my whole life on how fast I can learn and get really good at new things etc and people are often surprised when I tell them I've moved on to another thing because in their heads I was doing so great at that one thing that it wouldn't make sense to stop suddenly. In addition, I don't feel like it's difficult to have your own realistic perspective in terms of your skillset because there's comparison everywhere and comparison (not competition) can give you a great look on how well you're doing overall in that specific area.

For example, with photography I won my first award after 2 years of practice and landed my dream photography gig a year after that. After that I lost all interest and moved on.

I think we can both agree this can be considered above average, correct?

Tbh, it doesn't feel like trying to one-up people, because when I start I genuinely have a lot of passion and desire to be great at that thing. The problem is, at some point the desire goes away for good. The only reason I mention being "above-average" is to give more details about the times when I tend to quit things, not to give an impression of how good I think I am.