It's bullshit, man. I'm not circumcised and I've never had any problems. Not saying you can't have problems but there are tons of potential complications and risks associated with circumcision too. Just remember that having a foreskin is the default state of nature. If you're a Christian, you can look at it like, that's the way God made you, to alter it is going against God's design. If you're secular, you can say that millions of years of evolution decided that having a foreskin was an evolutionary advantage and serves a purpose otherwise it wouldn't be there.