On multiple occasions I have resigned from jobs after 2-3 years with no clear plan for the future, let alone another job lined up, simply because I didn't like my current job anymore.
On multiple occasions I have poured hundreds, maybe thousands, of hours into projects and start-up ideas that never had a realistic chance of working out. I did this safe in the knowledge that I could run down my finances working on some fun speculative project and someone out there would give me a job to let me pay the bills when I needed it.
So I certainly haven't maximized within my career but I chose a career well.