You can't undo a circumcision, you can however get circumcised later in life if you so choose.
I'm uncut, I've never had a girl think its weird. I've never had a medical issue with it, I've never had an STD. But most importantly, I'm intact. I've never had a part of myself removed for vanity reasons.
Circumcised penises need plenty of lube to have unprotected sex, whereas uncut penises need less lube. So if sex is lasting any longer than 15 minutes when the girl usually stops making enough slippery juice, uncut wins.
I think a cut penis looks weird.
Leave the choice to men who are old enough and mentally able to decide what is best for themselves, rather than cutting up innocent babies.
If you can circumcise a baby, why can't you tattoo a baby as well? Both are permanent, and some will like that fact it has been done to them and others will resent it.
It's just like religion, why are impressionable children allowed to be told that any one religion is the right religion? There are hundreds of religions, and most children are told only one is right, and you have to believe the one we tell you to believe.