Am I making a domain name mistake?

I am wondering if I am making a mistake. I have a great idea for a cartoon brand. I was going to register the two domain names www.thenamenam.com and wwwnamename.com No, namename.com is NOT the real name. Anyway, today I registered www.THEnamename.com. I found out someone else registered the other name www.namename.com in February. Oh well. My question is, would it be a mistake to create a brand/website that is so close to the other domain name? I have no idea what the other website is about. It’s not up yet.
I appreciate your input.

First off it doesnt matter what domain name you register if you r able to create a good site and get traffic

But the domain name is a title name.

If they’re also using that as a trademark and, say, you want to make yours arguably riding on that, yes.

I better do a trademark search online.

Keywords having domains are very best in the industry if you want to optimize your website for search engines. Matt Cutt’s in a statement cleared that there is no matter which extension you are using for your business.