Heh... speaking of looking at people odd... while working in a field kitchen for a while, the cook asked me for a "long deep insert" (Standard metal trays, long, short, deep, and shallow, inserted into hay boxes and into the serving thingy's in the messes for anyone who didn't know) ... I was very confused... I thought he was pulling my leg, as the fellow was a tad perverted...
With regards to the horse c**k, here's an example of how slang gets into your vocabulary and you don't really think about it, I watched somone search a stack of loan cards for a good 15 minutes looking for a reference to horse cocks.