I think the meaning of this is about how he had so many good times with someone
summer romance but as time goes by he questioning weather it still there or its fading
away. But the he will always carry the memories with him and they had "nothing to lose
but everything to gain" is saying they couldnt have lost anything but made something special
like a relationship or a great friendship
and he saying that all of that "it was worth it in the end"
they are still on and happy
I think the meaning of this is about how he had so many good times with someone summer romance but as time goes by he questioning weather it still there or its fading away. But the he will always carry the memories with him and they had "nothing to lose but everything to gain" is saying they couldnt have lost anything but made something special like a relationship or a great friendship and he saying that all of that "it was worth it in the end" they are still on and happy