What exactly are these mythical tax rules? How do they work? What do you need to qualify for them?

Wouldn't it have bee great if you could have gotten your hands on a list of foods to avoid binging in the dining hall?

It would have been great to know their habits and awkward rituals before you showed up at one of their parties. 

Dress codes don't end after the pre school days: you wish you had thought harder before wearing the mini skirt to the office...

You don't want to get stiffed at the auto shop and you want to be able to change your own oil.

You could have saved yourself a lot of heartache if you had gone into every relationship knowing exactly why you should break up with him.

How does she have enough time in the day to get all of her homework done, work a part time job, mock you mercilessly, and sleep?

It's SO WEIRD going back home after you've moved out. Cue the waterworks at the dinner table. 

You have no recollection of meeting this person, but she sure know you: your name, your life history, what you're majoring in...

You need a job, like yesterday. A class that tells you exactly what to say during the interview would have been great.

This could easily turn into a horror movie if you're not careful.