Already there since this year @ 35, with kids. Previously retired at 23, with lower expectations. Don't consider myself a teacher - that was mostly luck.

However, common mistakes: Not demanding equity, not understanding equity and options, living in overpriced cities, thinking the latest technology is somehow more important than the one that stood the test of time.

I can't recommend the annual Venture Deals course from Techstars enough to really grok equity deals, as these are really where the money comes from, whether you are founding or an employee. In the US anyway, tax is an aberration.