i have a natural tendency to flip things around. this has been happening since i was very young
some old examples when i was a toddler:
key cars -> in fact my grandmother still fondly uses the "key cars" phrase
new brand -> i always loved getting "new brand" shoes when i was really young, i actually remember saying this phrase until i was around early 7ish so it took a while for me to correct that phrase.
some newer examples:
rocket wrist -> a co-worker wanted to get a wrist-rocket to shoot at pesky squirrels in his backyard but i kept calling it a rocket-wrist and i didn't even notice it until he kept correcting me.
"he threw the ditch into her" -> i was describing a dream i had and my sister corrected me when i mixed it up
i very frequently interchange noun phrases. there are probably hundreds of other times that i've done this and am still not aware to this day just because nobody has brought it up or corrected me.
i've also put dirty coffee spoons into the fridge and the cream into the dishwasher at work after preparing my coffee, good food into the garbage and it's clippings/wrappings into a pot for cooking, eating candy wrappers and throwing away the candy ... to name a few.
i always laugh when i catch myself doing this because it is funny to me. it's one of my childlike quirks that really small "backwards" things are extremely humourous to me, especially if it's grammatical. i don't get too stuck on it because i could use some childlike joy every now and then so i welcome the chance when i make a mistake like that.