In case this is you:
or if you have been living under a rock for 5 years...
...you may be interested to know that you don't have to wait until 2013 to know why the cake is a lie. From now until May 24th, Valve is offering Portal for free to PC and Mac users. Get it while it's hot, people!
Seriously, go get it now. There's a good reason this game won a gajillion awards, and even if you don't think you'd like it, you should get it and try it anyway. This game probably gets the most wide personal endorsement I have ever given to a game... Yes, it is worth signing up for a free Steam account to play it (since presumably that will be required).
People with no internet connections on the computer they play games on are exempt =P