Building the furniture isn't the difficult part, navigating the store and not having an argument with your partner is. Surviving Ikea is a marker of a stable lasting relationship.
I should also add the people that haven't seen each other for years who decide to have a long conversation with trolleys in the middle of the walk way, people that let their kids run wild and the people that decide it's a jolly jape to do the whole Ikea experience backwards.
However the hot dog at the end makes up for it all.