This. It's really easy to make money in hindsight. If you'd bought GOOG at the IPO in 2004 and held it until 2007 you would have had a 6.6x return. If you'd held it until today you would have had a 13x return, but a much lower IRR. On the other hand, if you'd bought Zynga at the IPO you'd be down 66% five years later and still waiting for it to bounce back.
It's a lot easier to make hypothetical money in the past than it is to make real money in the future.
On one hand, the only reason to work for a start up is to take the risk and go all or nothing. On the other hand, I would never invest in a start up.
I probably would sell off a huge portion (~70%) of equity before the start up reaches $500 million given the chance
We went out for $1B though (on raising < $2M of VC money)
Sadly I was not in that group of people