It is hard to rationalise or explain why you love what you love. But I have always been interested in science and maths, and in high school I was struck that you could use maths to understand nature and science.
The part you don't expect when you start out is all the people who come into your life wanting a piece of you, not caring about your wellbeing. The insane schedule is very difficult. Touring looks very glamourous but it's hard and gruelling - the travelling, the meet-and-greets - it was too crazy.