"I remember being in year eight, the year before high school, and absolutely loving “Tik Tok” by Ke$ha, and then six months later I got really into Animal Collective and Grizzly Bear and Yeasayer. I still love those bands, but I definitely went through a “you have to forget about the Ke$ha part of your life” thing."
She means she once use to enjoy listening to Kesha but now when she thinks about it, it makes her cringe and she basically wishes that she'd have known better when she was younger...
Apart from it being AP, that's not what she meant. She tried to ignore that part of her life where she liked Ke$ha or something because it was too "mainstream".