As a student pilot I used to go flying at odd times when it was less likely there would be other students flying in the training area. This was the result of a being freaked out by aircraft turning up in my windscreen on a number of occasions. It freaked me out even more when, what I always worried about happened a few years later in NZ;
http://www.nzherald.co.nz/section/1/...ectid=10367642