I'm paraphrasing the saying, "There's no such thing as an original idea anymore." People are far too quick to point that out when criticizing good creative work. Here's are some recent examples:
A young woman, Leah, sent a Lego kit of herself along with her resume to various agencies, trying to land an internship. She went viral and will very likely land a JOB. Personally, I did a similar concept years ago. I never went viral, but it helped me land my last two jobs. (and my packages sat on my creative directors' shelves for years). Sadly, I'll never be able to do it again, because everyone will now think I stole the idea from Leah.
Deutsch L.A. just launched a series of brilliant ads for Taco Bell breakfasts, endorsed by real individuals named... Ronald McDonald. Yea, W+K did a campaign for ESPN featuring everyday people who share names with popular sports figures.
That was sports. This is food.
The average consumer isn't comparing the two. Right now, they are smiling and considering a Waffle Taco over an Egg McMuffin.
So I say congrats to Leah and Deutsch L.A.. When you create work, don't worry if it's been done before, as long as you take steps to make it yours... Add the unexpected twist... Give it a different look and tone... It's also beneficial if the concept hasn't been done recently by others.
People will still criticize you, but if the execution is done well, those haters will secretly wish that was their idea.