I was always told that if you held a buttercup flower under your chin and it reflected yellow then that meant you liked the taste of butter.
A childhood belief about plants

others believed things like this
- If you held a buttercup under your chin and got a yellow reflection then you liked butter!— Tilly
- I believed butterflies taste like butterAnon
- My mother told me if I ate too much butter I'd get worms. I didn't eat too much butter...— Dicky
- I used to believe that the yellow sky during a sunset meant that people were peeing a lot.Anon
- i used to believe that red yellow and green meant "ready, set, Go!" on traffic lights..— cabagona
- I used to believe that the yellow light in traffic-lights meant Go Faster!— M. L. E.