Most of the time, I'd say imagination is a good thing. A great thing, even.
But sometimes, I think it can be a bit of a nuisance. It can get out of hand.
Take this street sign, for example:
I see it all the time on my way to and from my house.
Except when I see it, this is what I'm always picturing in my head:
Someone taking a leak. It's a bit crude, I know...but this is what imagination does. I see things that no one else sees. At least I hope no one else sees this. There shouldn't be more than one of us running around visualizing this on merge signs.