I think that part of this song means that when they went back to school or home or whatever their normal life was that even though things got back to the way they used to be, with all of their teachers giving work & tests and the norm or when their parents bugged them to get a job (they can take, take, take, take the kids from the summer) they still remembered all of the memories and times from the summer. And then he's asking summer for one of those memories. He's asking for summer to give him something to remember, so that when everything goes back to the way it was, he has something to think about.

My view:. I think it's trying to portray the feelings of when you know it's wrong to love someone, but you follow your heart anyways and you shut out all your common sense. And then in the end you get hurt, and you wonder why you couldn't have listened to your gut feeling in the first place. And I think the person's mad because they gave their ex so much power to hurt them, and in the end they regret that. And she realizes that even though she understands that he was a jerk she can't help but still loving him. And that's why she's mad because she's letting her heart win the battle over her mind. And she thinks that her heart always leads her in the wrong direction, and it tries to overtake her mind, and wins. I don't know, but it's just what comes close to my heart because I feel the same way at times.