我说 虽然夏天过去了 

I say: Though summer fades,

但遇见你 

to have met you

也算是没有浪费这个夏天

means this summer was never wasted.

You say: Though summer fades,

你说 虽然夏天过去了

you and I

但你和我

are only just starting.

才刚开始