"The first time you get your heart broken, it's the worst.
You've never experienced anything like that.
The first time you're in love, & you get your heart handed to you on a platter,
You don't know what to do with that, you don't know how to handle that.
The songs lyrically saying, the first one sucks
& it hurts a lot, & it stays with you for a long time.
And you're never really going to loose it,
You're always going to compare it to whoever your with after that."
Martin explains this on there youtube account,
"The first time you get your heart broken, it's the worst. You've never experienced anything like that. The first time you're in love, & you get your heart handed to you on a platter, You don't know what to do with that, you don't know how to handle that. The songs lyrically saying, the first one sucks & it hurts a lot, & it stays with you for a long time. And you're never really going to loose it, You're always going to compare it to whoever your with after that."
http://www.youtube.com/user/boyslikegirls?blend=1&ob=4#p/u/3/Qq7YeX8SybA
Says it better than anyone could :)