Finding out
Well, where I live right now circumcision almost doesn't happen, unless it is because of religion ( then you can easily find out ) or because of heavy medical problems. So pretty much nobody here gets cut just like that. On the other hand, when I am in Turkey I know that pretty much everyone is cut. So there is not much of a guess in my life so to say.
Yes, I always want to know whether they are - and if so, when and why! Always interested in those who, like me, were done as adults from choice.
I have known the topic come up three times in all-male company. Twice at college: once because a guy just asked outright who was (I think we had been drinking!), and another time because one of the athletic chaps had had to be circumcised, and it became a general discussion. The third was when I was teaching at an all-boys school and the HM put his head round the common room door and told us that X had been circumcised, and so was off games for a few weeks. That, too, became a general discussion about who was and who wan't. Turned out most of my colleagues had been!
I'm cut and this happened in my late 20th and it was by choice I'm still happy about it. I go to nudist beaches, to Saunas, nude bush walks and I see lots of cut and uncut cocks about and if it comes up in conversations no one is embarrassed, because it's a conversation amongst guys only.