To complete this goal: Go outside and do something awesome. Examples include canoeing, kayaking, whitewater rafting, rock climbing, camping, hiking, mountain climbing, spelunking, etc. It really needs to be at least half a day to qualify as an "adventure," preferably a whole day.
Why? I've been hiking a little bit in Hawaii and Colorado, but I've never done a real full out outdoor excursion or adventure. Maybe I won't enjoy it, but I want to try something new and get out there and do more things! If you've read many of these posts, you may be seeing a pattern emerging :)