I used to sling auto parts at the Dalhousie Crappy Tire.
Woman: Uhhhhh my husband asked me to get some oil.
Me: Well ma'am we have lots of that. Any particular type?
Woman: Ummmm I think he said.....Vaseline? Yeah... Vaseline.
Me (trying to not bust out laughing): Uhhh I think you mean Valvoline.
Woman: No, no, I'm pretty sure it was Vaseline.
(After a minute of that I just said we were out of Vaseline but had plenty of Valvoline. Sorry. 2 minutes later she left with the Valvoline.
)
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Then there was the time a guy came in who's oil filter had rusted onto the threads and he couldn't get it off. Holds up a butane torch and asks if he can use it to heat up the threads to loosen it. My manager and I go back to the warehouse and bust out howling before we both decide we have a legal obligation to not let this guy turn into the Human Torch. For god's sake don't do that!
Crazy times.