"out of pocket" huh?

Is it just me, or did "out of pocket" used mean that an expense was coming out of your own pocket?  How did it come to mean; out of reach, out of town, out of the office?

No kidding, I thought I was just hanging out with a large number of people who didn't know the correct use of the expresssion, but I guess I'm the one not in the loop.  How does the meaning of something like this get changed?

 In college, we would frequently change the meaning of words to suit ourselves.  My boyfriend and his housemates used the word "houl" to refer to partying.  It actually originated as a hockey player's last name, as in "Houl shoots; he scores!!!"  Somehow he and his friends co opted it to mean something completely different.  (and it could be a noun or a verb, as in "I got houled last night." or "We're having a houlathon.")  This same boyfriend called an angry mood, a "1947 huff".  If I remember correctly, that one had something to do with the huffy bicycle... But hey, these examples are only used among a small group of people, not an entire population.  And they're pretty ridiculous to boot.  How does a phrase like, "Out of pocket" change meaning with no one objecting, no one saying, "I think what you meant to say was..."?

Any ideas?  Examples of your own? I'd love to hear them.