Also not a pilot. I am terrified of heights yet am absolutely fine in airliners and used to love flying in light aircraft; I did a bit of gliding way back and was perfectly happy doing tight turns in thermals. However in recent years I've become distinctly uncomfortable with any kind of steep turn.
I can only assume the fear is a result of not flying much recently combined with witnessing several airshow accidents that involved a stall. Also reading too many accident reports I dare say...