"Leaving Google because feeling unfulfilled" is one thing. "Starting one's own company" is another. "Spending 6 months in SE Asia" is yet another. They don't

"Leaving Google because feeling unfulfilled" is one thing. "Starting one's own company" is another. "Spending 6 months in SE Asia" is yet another. They don't necessarily work together toward a common goal: you have to decide what is the most important to you. If you decide to leave Google because you don't like it, then obviously that's up to you, but if you truly want to start your own company, you have a much better chance of coming up with a good idea (and skills/networks to make it happen) if you work at Google than if you're traveling the world. Honestly I'm not sure how the travel and doing startup is even related. That said, you're young and if you're good you can always get back to Google (or another similar company). So there's no big harm in trying something different and seeing if it works.