This is exactly what I was going to reply with! IMO, if I were in Jake's shoes - I'd be able to look back at what I had BUILT; Twitter, Square, and be content

This is exactly what I was going to reply with! IMO, if I were in Jake's shoes - I'd be able to look back at what I had BUILT; Twitter, Square, and be content in those accomplishments. But that doesn't mean "OK, done here - good game." -- Everything I build I see as a stepping stone to the next thing I am working on, that everything prior serves as foundational experience from which to build upon. Even though I am not a developer, I am a builder. I design systems and networks and datacenters and hospitals -- I am not the ONLY designer/builder that works on these projects, but I can see my contribution clearly. And I am satisfied with my ability, and driven to add more value at every opportunity. I haven't made 300 million yet, but I keep on moving. Keep on going, no matter what. Finally, I try to learn from the experiences of others - avoid their mistakes, emulate their wisdom.