Learning from success or learning from failure?

Today was fun. I had lunch with one of the board members at CIGNEXYakov Soloveychik
(unfortunately Yakov still does not have a blog yet) and we were
talking about learning from success and failure. Yakov had an
interesting observation. Here is the gist.

A lot of learning happens from failure. While you can learn from
someone else’s success, it is not that effective as it is very hard to
duplicate someone else’s success. The circumstances are different, the
skill sets will be different, the posture is different – basically
there are too many variables that will prevent you from copying someone
else’s success.

However, failure is different. Once you know how a person failed,
chances are that you can learn from that experience and avoid making
that mistake.

So, what’s the summary:
Please don’t invest all your time
trying to learn how somebody succeeded. It’s important but it’s not
everything. Learn from someone’s past mistakes. What went wrong and how
you can avoid making those mistakes.