Watched water doesn't boil, as my friend Milan said. At least, your intent stare by itself won't make it boil. For water to boil, the molecules should get enough heat, they should have enough energy to start moving quickly and far enough from each other and stay there. They should have enough power to overcome the lazy tendency to stick together. Or so I remember from my high school chemistry class.
Sad but true - I act on something IFF:
1- I'm late enough OR
2- I'm envious enough.
Both conditions are fulfilled now.