You don't need to have the totality of perfectionism to achieve at a high level. I also like to be very good at stuff, I'm a high achiever myself and average is unacceptable to me simply because I know I'm not average. I know that from experience.

But true perfectionism would be unnecessary stress.
(I am sure this is going to be nothing new, but) your worry about perhaps not being competent now even though you always were in the past is pretty irrational and obviously unfounded. As long as you have a healthy brain that you keep exercising you'll be fine. This is not to say I never have such thoughts myself but I always know that's irrational BS.
Maybe this is Ne for you though? I read somewhere that ENxP's need to improve themselves all the time.
I do have that desire sometimes but then I'm back to focusing on what I'm actually doing. I suppose if I do things, learn things, achieve things, it does improve me in a way...
That's the key difference. You want to improve, but you're more focused on the "doing" of something and as a result of a lot of "doing," you become skilled. "Doing" has little to no attraction for me except in that it is a way for me to improve a skill I have. And yes, I would say it is an Ne thing. I know my own capabilities and can see the best possible outcome of a challenge, so it bothers me when I don't achieve it.
Ah, I also must understand to control just like an NT, I would say forget Keirsey

Though sure, I do like that kind of SP freedom and I do strive to have it.
Meh. Reading Keirsey just gave me better words to describe what I'm talking about here, like NT vs SP etc. If we had this conversation 6 months ago I would have given you the same answers, it just wouldn't have been in this type of language.
Anyway, I do feel uncomfortable when I can't answer a why and I try hard until I can. But for the emotions I already have a pretty nice explanatory framework taken from psychology theories. Anything beyond that would only be needed for practical purposes... (this can still be very interesting and not simple at all.) Maybe there's the difference then between us, you want to develop a totally new theory for everything all the time?
yes, i'm obsessed with reasons. I want to know how I, people, the world, reality works, but more importantly,
why it works. ​I can't explain it, its a subconscious drive.
Okay but it's not dominant Ti.

I mean I'm also not dominant Ti and thus I can take a bit of irrationality here and there.
True, but I think an ENTP's aux Ti works differently than an ESTP's aux Ti. When working with dom Ne, it functions to pick apart and analyze each idea that Ne provides, keeping/preferring the logical ones and either discarding the illogical ones or improving them until they are satisfactory in their rationality. So while we can tolerate the
existence of irrational ideas, we can't do the same for the
implementation of them.
That's not to say I'm some hyper-rational robot. I enjoy irrationality at times, like when I'm playing the role of comedian. I don't wait and think "hm, based on the crowd's level of laughter from that last joke, i should use this joke over that joke next because the content of the last"- NOOOOOOOOOOOOOOOOOOOOOOOOO! STOP! I just Ne my way through it. And the best part?
I'm really fucking good at it.
Perfect example. Every Friday is dress-down day in my office. Jeans, t-shirts, etc. This morning I saw, in my pile of clean clothes on my floor (next to my many piles of dirty clothes), a graphic t shirt that says "anyone can be cool, but awesome takes practice" with a headshot of a dude with a mullet on the front and
knew it was the right shirt for today.
Couldn't explain it to you if I tried. But I'd be lying if I told you I haven't gotten 5 comments on it and made 3 other people outright laugh at it... and i've only been in the office for 2.5 hours.