There's a great scene in Stanley Kubrick's film 2001: A Space Odyssey where HAL says “I am putting myself to the fullest possible use, which is all I think that any conscious entity can ever hope to do.” The fact that HAL is a computer is disconcerting enough but even more unsettling is how it nudges the viewer, who is in fact a conscious entity, to ponder am I putting myself to the fullest possible use?
Occasionally, I'll hear the phrase What's the meaning of life? spoken in a casual conversation. I say "phrase" and not question because it's usually said more as a punchline than an honest inquiry.
The meaning of life is at the core of HAL’s quote. He (it) has found it: I am putting myself to the fullest possible use. Of course, the word "use" here does seem subjective. If HAL were a philosophy professor, I doubt he would tell his students that his reference point for usefulness was, in an a priori sense, THE reference point. HAL seems content because he has found his own fullest possible use.