what lessons we can learn from successful entrepeneurs?

Do you mean entrepreneurs?

One quotation I've heard several times struck me as I read your question: "Try again. Fail again. Fail better." (Samuel Beckett, http://www.tomphillips.co.uk/portrait/sbec/)

Another thing I heard several years ago is that Samuel Hershey failed six times (or maybe it was more or maybe less!) before coming up with his idea for a chocolate candy business.
http://www.hersheys.com/discover/milton/milton.asp

In other words, those who are truly driven do not give up. They learn from their errors/failures and try again.

=)

be send me