What’s a good topic sentence or thesis for a definition essay on success?

For this one, I suggest you reflect on what you think success is. It won’t be easy. Perhaps you can resort to the traditional brainstorming method. Write down as many things as you can think of that mean success to you. After you’ve toyed with the hundreds of ideas you come up with, you’ll select the most inspiring to fit into this one sentence. Your thesis cannot be one of your definitions of success. It has to be THE definition of success based on all your ideas, and in one sentence. The rest of the paper is supporting this one sentence; otherwise, that sentence was not your thesis. Hope this helps.

Your thesis statement does not disagree with the original statement you said the topic should be about — because in the US most people DO feel success is measure by what you have. I’d fix your thesis statement to be a bit stronger, such as its measured and impacted by society, family, and experience.