I'm not sure at my half way point I've yet discovered any grand mystery of the universe, but I feel at peace with my life choices and grateful to be afforded the opportunity TO choose them. I am grateful that I've never lost a love of learning, and grateful the world is so big and grand and full of opportunity to always experience new things.
For example, did you know that you can drink spring water right out of the ground without filtering it on the Appalachian Trail? (Not after it's flowed for a few feet, but as it's coming, unpolluted, out of the ground) Or if you use a long straw to blow on your campfire, instead of just your mouth, the concentrated air will help the flames really burst to life. Also, hang gliding is a much more relaxing and serene form of air adventure; I was surprised to find I liked it better than skydiving, which was actually a bit painful. Diving chest deep into water that's below freezing will force your body into defense mode to warm your core. (teeth chattering, shivering etc) It will also sacrifice your extremities for the sake of your core. This makes normal functions like climbing a rope or picking up an object infinitely more difficult.
I wouldn't say any if these individual adventures have changed the course of my life, but I would say that choosing to have them regularly will indeed continue to change me forever. And that's all I ask out of life: adventure, growth and change.
If you find yourself stuck in a rut, go do something new. Try some escargot or take a boxing class or volunteer at a refugee organization to meet people you could never possibly share the same story with and LEARN. You never know who you're going to meet or what you're going to gain, but the chances of meeting someone new or experiencing something new while stuck in the same routine day in and day out are slim. The people we have yet to meet are the ones who bring us new opportunities, and the things we've yet to do are the things that teach us something we don't know about ourselves. It's always worth the risk.