God said:
Certainly, ego can motivate you toward success. At the same time, great ego does not make you great. Great results are nice, very nice, very wanted and very welcome, yet results do not sustain you. All the success in the world does not sustain you. All the money in the world is nice, very nice, very welcome, and yet, as you have heard, you can't buy happiness with it. Success is not an external matter.
Just as the secret of happiness as well as unhappiness lies within, the same secret goes for success, of course, regardless of what you say qualifies you for success.
By no means do I say you are to scoff at success. Success is worthy. All kinds of success are worthy. Be wealthy. Be a movie star. Write a great novel. Be famous. Invent something wonderful for mankind.
However, sooner or later, success in the world wears out. It's not everlasting. It just isn't enough for you. Even if the world bows down to you, it's here today and gone tomorrow. Let love over ego motivate you.
There is no being the fairest of all as the queen in a fairy tale wanted to hear every day. That's ego. Sooner or later, ego lets you down. That's the nature of ego.
Have fun with fame, success, rolling in dough, etc., yet keep your wits about you. Don't let world success go to your head.