Okay so here's the thing. I just bought my first big-boy bed (a double) and forgot my pillows when I moved. I don't know much about this stuff. I know there's not much to know but I know even less.
I went to Linen World because they had two feather pillows for $50 sale which is pretty good value. I saw one I'd picked up was Queen and asked if that's what I use on a double bed as I thought I was looking for "standard" size. I know you use Queen duvets and duvet covers so why not pillows? She told me she thinks they're the same thing and it would fit my pillow case, etc.
Then I get home and realize I bought 1 standard pillow and 1 queen pillow. Now I'm an idiot for not realizing this, but how didn't she? It's your big sale item advertised in the window and you don't know you have both sizes available? All sizes are thrown in on the same shelf? I'm allowed to be dumb about this stuff but you work at a bedding store and don't know there's a difference between standard and Queen pillows?
Now I have 2 different size pillows on my bed and it will drive me crazy forever and ever :)