Core beliefs include:
Look out for Number One
Find a bed, or some other somewhat appropriate place to sleep.
It seemed like a good idea at the time.
Things which have value to you (like money or friends) matter not to Sir Not Appearing. Likewise, things which have no value to you (like broken road cones) have tremendous value to Sir Not Appearing In This Film.
Time travel is a very real and distinct possibility for Sir Not Appearing In This Film.