Whirleybird,
If the world of pilots would know everything there is to know about carburator heat, the why's and the when's, then nobody would be talking so much about it, you wouldn't find safety leaflets about it, and at the end of the story... crashes due to iced up carburators would be almost non existent.
I've found this to be a very interesting topic, since I'm not flying a C150, but I'm about to fly one for the same reasons as yours (it's cheap!). Better safe than sorry!