> I liked math and physics and economics and even chemistry,

I think the reason is that these subjects give students a sense of instant gratification and instant empowering. Every concept and every theorem could be a breakthrough to my problem-solving skills, and I can immediately see how I can solve more problems through the learning.

But of course, nothing gives more instant gratification than CS. I can try and build things via my keyboard at any time. The learning and the associated work does not get better than that.