Sooner or later in your life you ARE going to find yourself trawling your way through the sewers or visiting catacombs if you are to have a hope of saving the world.
Being an orphan is a sure fire way of getting roped into saving the world.
That the most lethal magic users in your party are going to die............. a lot!
That everyone you know can become a Jedi/Sith (KOTOR II)
That nothing can inspire such a high level of anger or frustration than a level you can't beat (especially when it can be easily beaten by an average 3 year old)
That resting in an inn can cure even death!
That though the general public will let you walk in and take their stuff, shops will still charge you earth for a sword you need to (wait for it) save the world and then you will find in the next area of the game for free!
That no matter what you buy, it won't be as good as the thing you took from the hands/paws/tentacles of the cold dead bodies of your enemies.
That the best equipment can be trumped by a simple + sign, as in +1 sword of wounding.
That for some weird reason the boss who has 65 million hit points to your 4,000 will only damage you by 500-1000 hit points despite semi conquering the world.
That bosses won't ever point out that 4 against 1 is unfair.