A few points:
1. I'm not sure you've said how you will be travelling. But assuming you'll be flying the long-haul legs, don't be too fixated on actually going Round the World. You might finish up doing a lot of flying, and seeing big cities, but not get out into the country too much. If you buy a RTW ticket, try at least to get one which leaves gaps for you to fill in overland (and sea) - eg flying into Bangkok, and out of Singapore; into Sydney and out of Perth; or into Cape Town, and out of Harare.
2. That said, don't be the sort of traveller who almost entirely neglects big cities. Often, the capitals, not the wildernesses, are where you see the real face of a country, unattractive though that might be on occasion.
3. With great respect, try not to be as upfront and brash as your language indicated when you first posed your Question here. You are clearly a go-getting young person, but some qualities (enterprise, know-how etc) much admired in the West are less appreciated in other parts of the world. Almost certainly, there will be times when you are brought down to earth with a bang, and it will hurt less if you don't have too far to fall.