Yes, it's been done before, but not by you. Walking across a continent will get you in shape, give you a good tan and give you great stories that will get you far at parties for the rest of your life. Put a green spin on your adventure and promote walking instead of car use. Make T-shirts that say, "If I can walk across America, you can walk to work." Get a friend to go with you for safety and conversational opportunities. Don't use a support vehicle because that's cheating. Walking west to east will be slightly easier because the prevailing wind will be at your back. Use trails rather than roads, and it will be a more pleasant trip.
If you are single but don't want to be, don't waste your time on Internet dating sites. Be bold and travel to Turkey, making a vow that you won't leave until you have discovered the man or woman of your dreams. Use your poor or nonexistent Turkish skills as a means of getting to know people. As your language skills improve, you will become more able to function in Turkish society. Visit Hagia Sophia in Istanbul. It's a very popular tourist destination, and there will no doubt be beautiful women and eligible men there for you to get to know. Marry the person of your dreams, and now that you speak Turkish and are married to a Turkish person, stay there happily for the rest of your life.
You don't have to travel to foreign lands to be adventurous. In modern adventure, anything goes. Reject the modern altogether and live in a tree, for a year or for the rest of your life. This will teach you a lot about horticulture, the passing of the seasons, your own abilities and who your real friends are (they're the ones who will visit you when it means climbing a ladder into a tree). This venture will also get you an article in the local paper. Build a small platform for sleeping, but don't build an elaborate treehouse. That would just be living in a house in a tree, which isn't the same thing as living in a tree.