[skdoo]

1. Thinks "I really need X... why doesn't it exist?"

2. Domain expertise in X

3. Thinks "I could build X!"

4. Actually builds X

The intersection 1+2 occurs often, and 1+2+3 more recently. 2+3+4 are fun for hacking. A PhD thesis is 1+2+3+4, but with a very limited 1. The startup I'm at (my first) is the first time I've worked on something that strongly intersects 1+2+3+4.