On a six-hour train trip through Eastern Europe several years ago, I counted up the dozens of countries I had been to and realized I was in reach of 100. Doing a quick time-and-money estimate in my journal, I calculated that the cost to get to 100 would be about $30,000.
My first thought: only $30,000? My friends were buying S.U.V.s with that kind of money. I could have a large vehicle or