"A cynic is what an optimist calls a realist."
Why do I say this? Well, take a look at what an optimist is. An optimist looks for the good in all things, or try to look on the bright side. In real life, this doesn't work awfully well.
Why not? Well, not everything has a bright side. Does HIV/AIDS have a bright side? Only if you're Fred Phelps waving around a sign that says AIDS KILLS FAGS DEAD. How about sweatshops? The only optimists there want the shoes and soccer balls made cheap, and are more than happy to pay some kid 10 cents a week to work. Capitalism really worked wonders for that kid, eh? I bet he's not doing radio ads for Hooked On Globalism. You won't hear his cute voice saying "WTO worked for me!" Drug addiction treatment? For the average person, it's like Sam Kinison said, if you're able to afford drug treatment, you really don't have a problem yet.
I prefer to be a realist, that is, someone who subscribes to realism. I try to look at things as they are, seeing the good or the bad, but not necessarly trying to find either one in everything.
However, a true cynic would find bad in all things, no matter how good most people would believe something to be. A realist is generally be able they see it. Hitting the Powerball jackpot? A cynic would probably complain about how many people are going to ask them for money. Personally, I'd be overjoyed, and I figure for that much money, I'd be more than happy to deal with it.
Of course, one is bound to be more vocal about what they find to be bad. This is how realists can seem cynical to an optimist.