I wondered if I'm the only one in this situation.
Currently, I am breaking my records and moving up the rankings for Doom E1 ITYTD. At the beginning, I watched my runs and I was happy... But since the Top10, every time I watch the replays of my runs, I only see my mistakes; I no longer have fun watching them... I still have fun DOING the runs, but watching them "frustrates" me.
Am I the only one in this situation or is it something common with SpeedRunning?
I’d say that’s common in any competitive environment where you’re incredibly competitive with yourself and you end up focusing on your potential improvements in what you’re doing. It can be very productive to identify those mistakes and practice to fix them, as it can improve your runs. The important thing is to try not to let that consume you - if you always focus on the negative and what could be improved, you’ll never be satisfied with your time/run and you’ll always strive for perfection. There is no such thing as a perfect run, and trying to get it will drive you nuts because you’ll never get it. That can mess to burn out and a general dislike for the hobby which is obviously not good.
You’re not alone in being competitive and always wanting to improve, but always remember to notice the positives and don’t let the desire for perfection consume you. Then you’ll quickly find yourself not having fun at all with the game.
Yes, this can happen. When you get better runs and better placements, your standards for yourself also go up and it becomes harder to accept any mistake you've made - or at least, that's how I interpret it. I think it's more likely to happen with shorter runs, where you're so focused for those seconds or minutes and then after you're done, you finally get a chance to review it. A brief pause or timeloss to a mistake suddenly becomes glaring when you're no longer playing it.
As Timmiluvs said, try not to let it consume you. I find it easier when I instead think of what I've achieved with the run - after all, a new PB is still a new PB even if it's got these problems in it, and the important thing is that you're trying. Everyone is different so my way of dealing with this may not work well for you, but I still figure it's worth mentioning.