We're not saying you don't have a mind like a steel trap. Hypothetically speaking though, pens are really cool for recording cards and goals and stuff. Why not keep it right on your whistle where you can get at it most easily?
There's even a rubber stylus tip on the end, which we think is really handy for keeping sharp points out of your pockets (we are not the only ones to have stabbed ourselves with a pen, don't even pretend). Keep one on your key ring too!
Dimensions: 8cm L x 1cm D / 3” L x .5” D
(Whistle not included)