It's really interesting how Aubrey's confession here kind of implies she really didn't try that hard to reach out for her friends. It's when she says that Hero always seemed to be busy studying. We know from what Kel said that Hero was in a depressive slump for almost a year. So either it took that long for her to try reaching out to him, she never tried prior, or maybe that's just what his parents told her when she knocked on the door. Either way...it doesn't seem like Aubrey tried that hard. The Aubrey at the end of Memory Lane says she always assumed her friends would leave her one day. So it seems like Aubrey just assumed this was that one day and grew to be upset at them. It's tragic, but also upsetting. It's upsetting how quickly they all gave up and let themselves fall apart after Mari died. Aubrey assumed they all abandoned her, Hero shut down and then started running from the memories, Basil avoided them because of what really happened, Sunny shut down because of what he did, and Kel stayed out of it all because he was afraid of making things worse. It must have crossed their minds at some point. At the swings, Aubrey admits that she always thought about being there for Sunny. But she never did. And as far as we know, none of them ever really tried.
It's been talked to death, but I'll still mention the detail of Sunny backing away after Aubrey finishes talking about why she was bullying Basil. Even if Sunny might not remember, he still knows it was him that ruined the album. This was all his fault. It's always been his fault.