First thing, anything less than a year is visiting. Most of these guys are talking about their experiences traveling, not the same thing.
Second thing is it's not an "adventure" after the first couple of years. Your still going to have to go to work everyday, pay taxes, shop for groceries, mow the lawn, paint the bathroom....... If your life sucks and you think that everything's going to change because you live in a different spot, your sadly mistaken. Now if you want to move to Japan because you like the culture, or Gold Coast for the beach life, or NYC for your career, do it. If there's a reason, do it. If your just bored, don't bother.
If you decide to do it, you need to be self sufficient. If you run out of cash and it's a week to payday, there's no one there to bail you. If you don't know how to register a vehicle, you work it out. It's all you.
You need to accept that you that you'll lose contact with most of your friends. It will be cool for a few years, you'll visit them, they'll visit you, Skype etc... But it'll fade. You'll only stay friend with your closest.
If you meet a girl and have kids, your parents and their grandchild will not have a full time relationship.
When you loose a parent, you'll feel guilty that you didn't spend enough time with them.
If you can get past those downers, your all set. I did Europe to North America 7 years ago and it was great for me