I've heard of it, but don't need to try, still have mine. Guessing there would have to be some measure of foreskin left to be able to stretch it. Don't think it would work if you're tightly circumcised
No, I do not need to do this as I am already uncut.
But no, it isn't weird and I don't think it should be painful.
On weirdness, I think most people probably don't give much thought to their circumcision status as it is all they have personally experienced and their dicks seem to work well enough so they're happy. But most us are presumably aware that there is the opposite status, i.e. if we're uncut we know that there are people who are circumcised and if we're circumcised we know that there are people who are not, and may have seen people whose dicks are like that. In the case of someone who wants to try restoring he may also be aware that having a foreskin is how it was before someone decided to cut it off without asking him and some anti-circumcision campaigners claim advantages to being uncut. It is completely reasonable, therefore, to wonder how one's penis would be in its natural state and, upon reading about restoration, consider trying it.
As for being painful, being stretched is how skin normally grows. For example, as your legs grow and you become taller, this is lead by the bone growing, which is also why it stops when the growth plates at the ends of the bones fuse. As the bone becomes longer it puts tension on the muscles and skin which then respond by growing until the tension is back to the former level. So if one was to find a way to hold the remaining skin on his penis in a position in which it was under slight tension rather than being relaxed, that would cause it to grow. If, as it grows and the tension becomes less the owner then adjusts to re-apply the tension then it will grow more, stopping when he is happy.
I think it is important to understand that restoration is not complete - one can get the remaining skin to cover the glans but the skin thus obtained will not have the same density of nerve endings as the former foreskin.
To get better answers, though, it would probably be worth googling foreskin restoration and seek out people on a forum dedicated to it.
I have a friend who did that and he said it wasn't painful at all and now he has a fore-skin. It took him about 6 months to stretch his skin. He even put some weights on his skin to make it hold in place over the head of his penis.