Very few people have that luxury. The career path for your average software dev in Silicon Valley does not have a lot of interesting work involved -- it's a bunch of middleware stuff like parsing data, CRUD operations and updating documentation. It's the 21st century version of being an auto mechanic -- super interesting at first, but there's a definite ceiling on the knowledge.

There is only so much interesting work to go around, and you're usually not going to be doing it. You can seek fulfillment at work, but you also have to be prepared not to find it. Seeking fulfillment elsewhere is the secret to not burning out.