Portfolio? What portfolio?

Just in case you don't know, my future plan is to get into an advertising agency in Toronto, and to be specific I want to be an arts director / creative director.

A problem I have encountered, which also applies to some people I know, is that in the hiring process they require a portfolio. Now, what the heck is a portfolio? What does it look like? What do I put in there? I dont' know if I did well research on Internet, but I have rarely came across any creative director portfolio. Yes, there are plenty of websites of them showing off their work, but how does a physical portfolio looks like? Adveritisng people have been telling me that a portfolio is almost a requirement, yet they don't tell me what it's supposed to look like. How am I supposed to start building one if I don't have anything to compare it with?

Another problem, beside NOT knowing what a portfolio looks like, is what kind of material I can put in. You see, at York they don't teach you how to build a portfolio, nor they give you an assignment to design an advertisement. All I do at York is read about communication theories and write extensive essays about them. But how am I supposed to gain experience?

Thank goodness that becoming a VP Communications for McLaughlin last year, it was probably one of the wisest decisions I have made to start my future. If it wasn't because I was VP Communications, I would have no experience building websites, or designing flyers/posters to put around campus. I wouldn't know where else to grab that opportunity.

A lot of these kind of jobs require past experience doing similar stuff, but how am I going to get experience if nobody hires me to do that kind of job?! How am I supposed to learn how to operate Photoshop, InDesign, Dreamweaver, Flash, Java, etc? I have to do it all by myself. I taught myself how to use photoshop, and now I'm teaching myself how to use InDesign. I also had to take an elective course that taught me about the basics of HTML and CSS. Another good decision. Ugh, Communications at York isn't as useful as I thought it was gonna be. I should have applied to a college in the first place, maybe I would have gained more experience.

One of my friends applied to the Creative Advertising program at Humber, and they required a portfolio. Of course she didn't have a portfolio because nothing she did at York required her to make any kind of that work.

How do advertising people expect me to have super amazing 10 pieces of work (the just 'ok' ones don't count) before I start the job and right after graduation? This is frustrating >:G

Closest thing I have found on Internet