Yeah, in some cases we're carrying a canary in a a coal mine down there if we just pay attention. With all the ED commercials, etc... and my aging, i was worried about that after I got separated and there was no wood in the tree for several weeks. Talked to my Doctor and he said it was probably stress. Once I got that under control, it was returned to normal operation.
Something else I'm convinced of was that when I got a vasectomy it "changed" things down there too. Not functionally really, but changed the way an O is achieved and "feels". Became much harder for me to get there from a BJ after vasectomy and I'm convinced that was the culprit. I think they try and bury negative results like that from any medical procedure or scrip.