[kcdev]

I can't imagine you'll enjoy working elsewhere if you're not happy at Google. If you're an entrepreneur at heart, you'll likely not feel fulfilled until you're working on your own product. I'd say stick around Google (at least for the paycheck) as your mentor suggested until you have an execution plan. Also, if you decide to find another employer in the future, it will be more difficult to explain that you quit because you felt "unfulfilled" (that would scare me if I were considering hiring you); but if you quit to start your own company, that's a commendable act.

[theparanoid]

I have never regretted leaving a job. The only regrets are not leaving sooner.

[kcdev]

Did you have another job lined up when you left?

[theparanoid]

No

[nakedrobot2]

If you're really an entrepreneur type, then your discomfort for working for a huge company will never go away.

Leave the squishy free breakfast huge happy company now and don't look back. You were never that googly to begin with, were you? :)

You are young and fresh, go see the world, see what else is out there. Go!

[posguy]

This was me when I left my last job, I have to say I do not regret leaving one bit.

[mbrodersen]

What on earth makes you think that Google is the best possible place to work? People leave Google all the time pursuing something better.