I'm now learning Spanish. I actually learnt Spanish for a year and a half in university, but have forgotten everything I learnt/French keeps taking over as that's my dominant second language (is there such a thing as a dominant second language? There should be).
I highly recommend it. It's free, and easy, and how cool is it to be learning another language as you go about your day?
In further Monday advice, aim to avoid splashing mouthwash in your eye in a bout of over-enthusiastic tooth brushing. That stuff hurts.
Nothing like a little self-improvement to cap off a Monday, am I right?