A few years ago, I learned the shorter catechism. It was a worthwhile exercise, but needs constant practice. I just found someone who has mad a set of flash cards, ready to print to help learning the 107 questions. To find these, follow the link: Westminster Shorter Catechism Flash Cards | D A N G I T B I L L !.
Knowing the catechism proves helpful in many circumstances: when listening to sermons, when preaching, doing Bible studies, talking with a fellow Christian… Reading through Stuart Olyott’s “Preaching pure and simple”, I could see the influence of the shorter catechism on more than one occasions when he explains some doctrines.