Lack Of Peer Pressure
When I was a student pilot, I was lucky to have some grizzled mentors. There were a lot of do this and dont do that admonitions, a lot of tips regarding shortcuts and rules of thumb, plus some sage advice about decision-making. A lot of that advice could be broken down into the old Its better to be on the ground wishing you in the air than to be in the air wishing you were on the ground genre, but it was often accompanied by a Let me tell you what I learned the hard way kind of introduction.