Quote from Ted in Robin 101
Marshall: What are you guys doing with Barney's secret Robin notebook? Let me rephrase that. Did you two ladies lose some weight? Lily: What do you know about this, Marshall? Robin: Why would Barney have a notebook full of information about me? Marshall: Well... [cut to a college classroom:] Future Ted: [v.o.] The truth was Barney was taking a night school class taught... by me. Ted: Welcome to Robin 101.