My first close call was recovering from a PFL with instructor in the middle of nowhere in particular. I had added power, turned off carb heat, trimmed out and had a look around a few hundred feet AGL to see off my right wingtip another highwing that I was about to climb in front of.
I lowered the nose and the right side got all pernickity about what the H... was I doing??? Said there was another airplane. WHERE ??? Over there pointing to the right wing that blocked the instructors view -- Whereupon the left ashtray bounced off the ceiling as the instructor pointed the nose straight down from a few hundred feet up
Started flying again a few years ago after a long hiatus -- now there's all sorts of close encounters. In a high wing in cruise, I like to add a hundred feet and have had one occasion to be grateful. Flying gliders there's other gliders popping up all over the place, even on long cross countries. In the Fall, the towplanes blend in against the foilage, but the white glider behind makes them easier to find
There's three SEPs I've had a good look at during XCs -- plus two twin turboprops, one of which I saw and was grateful he was going at a altitude between me and another glider sharing a thermal; another that ATC dumped me in front of that I used a near 90 degree bank to avoid
I saw him from well away, but he was really trucking.
After flying with other gliders in thermals, you begin to learn just how wide a turn can be, even steeply banked a low speed.
Then there's dodging birds. In a glider they're pretty good at missing us, but I've collected a bird at night.