Why do people forget, are unable to think about more than 4 things at once, and think slowly?

Okay, so I was wondering.

What evolutionary advantage is there in forgetting?

Some people have brains which are capable to remember almost anything, but most people have bad memory.

This makes no sense, because we have a very large brains, yet a simple computer can remember much more than we can.

I usually write things down because remembering is very hard.

Like, I could think of maybe 20 things about farming, but when I start thinking and writing down for months, I come up with over 200.

But if I dont write down, I would very much remain on 20 because any new thing I learn means I likely forget some other thing.

So it seems that writing down things is important to have a body of knowledge to work with.

But why dont our brains do this?

Our brains think very slowly, much slower than AI, for example.

But they also cant think of more than 4 things at same time, in most cases.

Most people, when they weigh pros and cons, they have to take pen and paper because their brains cant work with many points at once.

The ability to forget helps us prioritize, think better, make decisions, and be more creative.

Spelling must take up a fair few mega bites.

Thus bring us to ( knowledge ) 

Most of my best thinking came after I started writing things down and thinking about many things. If I never started writing down, I would likely never get where I am.

I don't always think, but when I do, I think six things at once.

Somewhere on our body we have like a little hole. 

All you have to do is shove like a toothpick or something in it to reset.  

I think i might know where the little reset hole is , but im yet to put a pin in it. 

Imagin trying to forget how to spell the word ( garden ) 

That sounds way more difficult then learning how to spell it. 

Ive noticed 

Going to the supermarket then coming out and knowing where you parked gets a little more ummm harder with age . 

You can feel the exact thing that this post asks. 

Not sure it's actually possible to do more than one bit of data assessment at a time.

Perhaps several separate bits, quickly.

I think that BK underestimates the human computer somewhat.

I think every time BK does a post, an angel somewhere gets dummer Zuzu.