This is supposed to be shorthand for slow typists, but the idea has kind of backfired. You may have shown up for an AA, or Alcoholics Anonymous, meeting only to find that it turned out to be an AA, or Alligator Arousal, meeting. Worse still, the Pedo Bear group NAMBLA (North American Man-Boy Love Association) is often confused with the other NAMBLA (National Association of Marlon Brando Look-Alikes).
Evidence appears to show that acronyms were invented by the Greek goddess Acronyma, a confused sort who was assigned to work for the goddess of chaos, Eris. The less said about the latter the better, but they got their way when the goddess of dictionaries, Librariana, went on her month-long vacation every year.