The reminders will come, sooner or later. As (I believe) Steve Yegge put it: I've got a limited number of 5-year projects in me. As I've got less of those, it becomes more important to choose which one you pick.

When you're twenty, it feels like you can tackle everything. As you grow older, you realize that you can't even begin to learn enough to know all the things you'd like to tackle :)