Is is normal for your cat to be this dumb?

i had a cat that would take all the toilet paper off the roll. he is just being a cat.

I had one cat who wouldn't stop until he came tumbling down, bounced off the hot radiator and hit his head on the hard wood floor. It was a miracle that he wasn't hurt.
I taught Pooka not to climb (for the most part) by hanging a large piece of flannel on the wall next to the bed. She was able to climb up and fall back down without getting hurt (the bed is pushed up against the wall and I added pillows) A couple rounds of "NO, climb" followed by a gentle shake of the fabric worked with her litter mates. Pooka took a few more times.
They seem to stop when the climbing results in a tumble. Just make very sure they can't get hurt when that happens. You also don't want to start teaching them to stop until they are old enough to understand. Sweetie, Petey, Sprinkle, Twinkle (aka Pooka), Tinkle and Burp were about 10 weeks old (and heavy enough to pull down a regular curtain) when I stopped the climbing.

YEs my cat does it. But we got him to stop

At one time I adopted an adult cat (who has since passed away) who had NO claws (front or back). I thought how incredibly cruel that his previous owners had taken all of his claws away. I found out why, although I wouldn't have taken the same action as they did. He was a large cat and would take a FLYING leap against the woodwork and then S L I D E down. It was a riot! You might want to switch out of curtains and get blinds instead. Or, depending on the material, try one of those "PET OFF" sprays. In any case, it's not weird. I have four cats who stay away from my curtains because I say "NO!" very loudly and they don't like that. ;-)

First off, your cat isn't being weird or dumb. Most cats love to climb. We had a cat who would climb our screen day to the top where she would then hook her claws on the drapery and hang there. So she'd get stuck and we'd have to get her down. We've never really had curtains for our cats to climb, but that's a really similar scenario. Don't worry, though, your cat is being perfectly normal.