MICROBE. A very small animal that devotes all its energy to moving into the system of an entire stranger. Once in it begins to do light housekeeping on the aforementioned stranger's epiglottis. (For the meaning of epiglottis consult the first doctor you meet. If he doesn't tell you he's no gentleman.)
No matter how many good things our friends say about us, we are never surprised.
Nothing is so astonishing to us as another man's success.
Needless to say, a friend in need is a friend in the soup.
Nothing ventured nothing wonderful.