For more than 20 years, Green Day have been churning out three chord pop-punk gems that make you feel like you're 15 years old again (and if you're 15 and reading this now, you'll understand one day). They do it really well. Sometimes too well. But there's a good reason why some of those catchy riffs cut right into your brain -- you may have heard them before.

We're not accusing Green Day of intentionally stealing musical ideas, as all the comparison examples below could be purely coincidental. In fact, further down this list, there are cases where the scenario is reversed.

Let's have a listen below!

Pokemon/Mott the Hoople/Electric Light Orchestra vs. Green Day

You'll never be able to listen to any of these songs again without thinking about Pokémon.

Listen to Pokémon Diamond and Pearl Game Music (2006)

Listen to Mott the Hoople, 'All the Young Dudes' (1972)

Listen to Electric Light Orchestra, 'Telephone Line' (1976)

Listen to Green Day, '21 Guns' (2009)