User blog comment:PhoenixDragonSamurai/Definition of insanity/@comment-27329394-20140819154329/@comment-4389268-20140819174205

its because there are times Izzy acts normal at times. Remember in TDA she is the only sane person inside the submarine. Then there is a few TDI ep like Not Quite Famous and Phobia Factor in which she acts like a decent person. Every ep Sierra appears she acts crazy.

Actually Dave already went cuckoo starting Hurl (the howling like the wolf and crybaby part) and show many signs before that. and he voted himself because the believes he got no chance with Sky.

Again, like i say, i perceived those who are obsessed with their love interest, stalker or not, as insane especially after all the crap How I Met Your Mother gives for 9 stupid seasons.