I think what makes a person successful or not is what they did with the gifts God gave them.
It's not about money, status, the benefits package, or the great retirement at the end of it all. If you've done the best you could do with the talents and interests God gave you, and you have been obedient to Him, and you have given the glory to God, that is what I consider success.
Now, after I've said all that, can I say that for myself? Not really. But it's not too late.