I'd disagree with Mr Twain on this occasion. You read for many reasons, and entertainment of the time passing variety is perfectly acceptable, it doesn't always have to be about betterment (I say this as an unashamed fan of über-trashy novels)
No..... not heavy - just shallow. When you thought you knew someone for a very long time .... you were naively, completely, and totally wrong. Flying solo.... when deep down in your heart you did not wish this to be your future. Where did it all go wrong?