In reflecting on how much David Heinemeier Hansson still loves Ruby on Rails, he states:

In light of this, I strongly recommend that you find a vocation in your life where you just really enjoy the act itself. Not just the results, not just the external incentives. The actual work. There's not enough time to spend it doing anything else.

By the way, for those not familiar with David Heinemeier Hansson, he's the guy who invented Ruby on Rails.

Via Loud Thinking