Keep track of where you are at in a book and be motivated to try by young Wim.
 
We all love a rewards chart, on the back of this bookmark you can mark off 100 of your cold showers and or wild swims, mark them in pen to record your progress, or in pencil so you can rub them out ready for your next 100!
I can - I did!
 
( Either set a reward or be rewarded enough by the sense of achievement )