How do I stop being so dumb?

I (20m) feel like a complete idiot at times. Now let me emphasize, I am not talking about trivia knowledge, I am talking about general intelligence. I'm a killer at historical and political trivia. That doesn't make me smart tho.

I am so bad at basic instructions. Literally, all of the time, people try to explain to me how to do something and I just can't comprehend. Like, when someone asks me to bring something, I get completely lost sometimes trying to find it to the point of giving up trying. I learned how to tie my shoelaces at 17 and I still can't really do them properly and they constantly untie, despite having had my mother teach me for hours on end. I often do things in some stupid way, like repeatedly doing something an obviously slower and inefficient way, then I see someone doing it the proper way and I'm like "ohh" and I start making it a habit to do it the right way. Heck, I had constantly messed up doing the bed sheets and one time it just clicked to me and now I mostly do them right.

Today, I messed up. I was looking at a wardrobe with jackets which has my parents' too and since I know I had 2 blue jackets. One of them is a winter one but I looked for the one. I picked it up, it felt a bit tight around me and the size was just barely it and even less but I figured I'd just give it to my mother when I return since I was in a hurry(she's not that much smaller than me). Well, it turns out it was hers. I wore a female jacket to university without realizing at all. My mom was bewildered how I couldn't realize this is a female jacket (she doesn't know I went out with it). I feel so embarrassed right now, because I should have known its not my cloth to begin with...

My point is, I feel like a fraud. I'm really stupid. I don't understand stuff and I feel like if teachers weren't so forgiving in schools and I couldn't cheat in university, I'd have never been able to get where I am now. The thing is, I can learn trivial knowledge, but when it comes to "street" or "practical" knowledge or just common sense I suck at it. People often tell me clear stuff and I just can't understand it right away. Today again, some colleague was asking me to show the formula on the second row of one excel spreadsheet and instead I was just clicking the next columns like a dumbass. In the end I just gave up and gave him the mouse to click on it.

I feel I constantly get examples of how stupid I am and I just wonder... how can I stop being so dumb? No matter how many books I read I can't even properly tie my shoelaces ffs. Nothing clicks to me. It doesn't matter how good I am at some specific things if I can't do the basic ones. What training could I possibly do to get basic common sense, as vague as this question sounds? Please don't just tell me I'm not stupid, I need advice, not reassurance.