How did it succeed?
What were the parameters the success was measured by?
When did it happen?
Are the conditions still the same?
Who were the people/parties involved?
Is the organization vastly different?
Why do you think the previous success can be replicated?
Asking these questions will probably build on previous successes and it is better than not asking. But some are just too egoistic to ask. Fear of failure or failure of fear?
Do you fear previous failures?