told by my dad
A pessimist is someone who gets a new bike for their birthday, and looks at it, and says, "Well, it's nice, but I don't want to ride it. It will get all scratched and dirty and it might get stolen, and besides, it's not the color I want."
An optimist is someone who gets a pile of shit for their birthday and immediately dives in and starts digging. When asked why, they say, "With all this shit around, there has to be a pony in here somewhere!"