One example of this I recall vividly was when fishing for perch with my old mate Nigel Witham. The conditions couldn't have been worse - a cold, sunny December day. We knew we had little chance until dusk, but then you can't catch sitting indoors!
Suddenly, I came out of my daydream. The hairs on the back of my neck started tickling. "Nigel," I said, "I'm about to get a run". Nigel's curt reply was something along the lines of, "Don't talk rubbish, there's absolutely no chance for ages, get back to your dreamworld!"
No sooner than he'd finished when the buzzer went!
But it wasn't mine, it was his! Nigel's bait was just a few feet from mine, and the jammy git had done it again! The perch turned out to be our first 3 pounder.
This happened 20 years ago and was the first of several such experiences. I don't get them very often and I usually have to work for my fish the same as everyone else. Of course, it could have been down to accumulated experience; it could just have been that I subconsciously noticed a slight change in conditions.
I do occasionally however get hunches. I get drawn to a particular part of the swim, especially when I've been at a water for a while and perhaps got "in tune" with it. Or I may get a hunch to fish a particular venue, even when "logic" tells me that this is all wrong. Unfortunately it doesn't happen at all often. Once again it may be down to experience. But I've learnt from experience never to ignore these hunches!