Went solo in 4hrs. after some gliding 17 years before. Although I was probably ready for it, it came completely out of the blue, and I didn't enjoy it much, as I felt I needed more. As an earlier poster said, very sensibly, you need as many as necessary!!!!!. I also conceded at one point to my instructor that flying sometimes scared me. His reply was 'good'. When I queried why he said that, he replied 'then you will treat it with the respect it deserves'. I always felt that his remark was the best possible advice for a student, and I always flew with that in mind. You can never have too many circuits, as long as you always strive to make them better and not get complacent.