Luckily a few weeks ago, she asked me a question when my brain was fully functional. What luck!
Charlotte bit into a piece of celery and one of the strings remained dangling from the stalk. She asked me what it was. I told her it was the xylem, the transport tube that brings water to top of the plant. I love when I remember things from high school biology. I also remembered the experiment we did in high school to demonstrate the xylem.
I took a stalk of celery that still had leaves on it. We set it in a cup of water and Charlotte put in lots of red food coloring. We checked the celery each day to watch for changes. Slowly the leaves started to get a red tint. By the end of the week, the leaves were a beautiful flame color. 
I remember the actual xylem showing up red along the stem in high school but that didn't happen on our celery. Only the leaves turned red on ours. Maybe we needed more food coloring. Now Charlotte knows what the strings in celery are used for. I guess some of that seemingly useless information I learned in high school came in handy after all. Little did I know then that I would have a precocious five year old one day and that information would be really handy.
See kids, stay in school... you might need a random fact from biology one day.
