I agree with everything that is written here but I think possessing a few other additional characteristics would greatly help a person to succeed in whatever he does. These are passion, optimism in the face of failures and most importantly a genuine desire to see others succeed as well, even at your own expense.

The last attitude will help you attract like minded and trustworthy people (who could be complete strangers to you and not people you have helped succeed) to your circle and help build a strong support base. Hence I consider it the most important.

My gratitude to @crypto.piotr for directing me to this post.