Wouldn't call that obsession, it's merely having a purpose, which is part of the equation.
There totally is science behind it. You do realize that there's an entire field dedicated to it, linguistics, that exists to, you know, study languages, why they are the way they are and such?
It depends on why you need English in the first place. This debate has been regurgitated so many times it's kinda tiring, but I digress.
If I had to give you a boring answer, it would be that grammar is a critical component in any language to ensure effective communication. The reality is, by not doing your due diligence of learning and using the language properly, you're offloading work onto the listeners, hoping that they're smart enough to figure out what you're saying 100% of the time.
I'll say, it's easy to just be like "ah well this is good enough" and stop right there. Nothing wrong with that, and no one can fault you for it, not even the native speakers. Again, it goes hand in hand with my very first point: having a purpose. If you can afford to improve (and hopefully achieve perfection), why wouldn't you?
As for your previous comment, what can I say, congrats I guess? You basically figured out how babies learn to talk. I wanted to say I feel sorry that you hate English, but that'd make me a hypocrite considering how I literally just said part of the reason is having purpose. Clearly English doesn't pose much of a presence in your life (at least in comparison to mine), and that's fine.
