So...you're uncircumsized?

At work uncircumsized men came up in a conversation. Honestly, I’ve never been with one and I have never really known someone who was (that was open enough to say so). So, can someone please fill me in? Does this have any implications? Why would someone not be circumsized (other than for religious reasons)? I’m mostly curious about this. Any insight you could offer would be greatly appreciated.