If one becomes a pilot and then something happens and he has to quit, he could allways go to university at that stage right?
Yes but it would be difficult.
Let's say pilot X is made redundant and loses his or her job after ten years flying for an airline. At this time, X has a family and a mortgage.
X needs to get another job straight away, not spend three years at university getting the qualification required. In addition, X finds it harder to study with family commitments and an ageing brain.
Therefore, I would recommend doing the degree now, while you're young and know everything rather than later.
Cheers
Whirls