I bet a good number of them also think that was one of the best times of their lives.
Here's another bet: ask them if they want to do that again for at least 2 more times with different companies and unknown leaders, wonder if they'll take it.
I learned a tremendous amount, and my team accomplished some truly great things that will forever occupy a warm spot in my memories.
Most of the people I worked with on this project agree heartily with this sentiment. You don't have to become an AAPL millionaire on a wildly successful project to make the process of creation something of great enjoyment.