Phrases and Meanings-III : Drop in any time

I wish this phrase "Drop in any time" would only make up its mind about what it means. Most of us know that the dictionary is meant to be ignored and sort of pick up meanings by usage - but, heck, that can be done only for phrases that maintain some sort of constancy in usage. When a phrase is so indecisive about exactly what it means it really gets on my nerves.

An early experience had taught