Every time someone mentions iCarly, I feel old. This teen sitcom bookended my university years, 2007–2012, and as such its actors are my contemporaries even though they play younger roles. It’s easily the kind of show I would have watched had it premiered five years prior. As it is, I never got into it, and so I knew precious little of Miranda Cosgrove, Nathan Kress, or indeed, Jennette McCurdy. So when my best friend…