3 failed products across 2 different startups, over a period of about 3 years. I definitely feel I've learnt a great deal over the last few years. I've grown as a developer, but also learnt about things like management and marketing.
I think this is good advice. I've never worked in a corporate environment, and I might get a job just to see what that's like.
I'm definitely going to compile and reflect on all the mistakes I've made over the last couple years.