Quoting Grant Sanderson:

One of the best pieces of advice I remember receiving from a friend many years ago is that action precedes motivation. This is often useful on a much smaller scale. We feel most awake after getting out of bed, not before. A drive to exercise comes from the habit of exercising. It doesn’t go the other way around. But I think the idea that action precedes motivation applies to this bigger question of finding a career doing what you love. These days, I do love making videos, and I really do love teaching. But when I was finishing college, I had no penchant or experience with videos at all. And my interest in teaching was honestly only insofar as it scratched this itch to do more math. It was only by stumbling into a wacky career where I was doing both of them that I came to love them.