Learn a new language -- not in your house with headphones on, but in a country where the language is spoken and you get some cultural immersion, as well. Pick up some Spanish in Argentina, hone your Czech in Prague or practice your German in Berlin.
Do something from your bucket list. Is there something big you've always wanted to do? Do it this year. Go on a tour of Europe’s great cathedrals, see the pyramids or take that cross-country road trip of American-history sites.
Get out of your comfort zone and take that trip that you've always wanted to do but were afraid to. Always thought you'd like to go to Japan, but worried because you don't speak the language? Buy a ticket to Tokyo and get planning.