I was intrigued by the challenge to understand and be able to work with the Japan train system and schedule. Not easy at first since the degree of complexity is high (different rail companies, routes / stops frequently changing, trains may have more than 2 or 3 names, time tables and station descriptions often on in Japanese). But I did figure it out eventually and it was a lot of fun after that. What I like especially

1) You will always be able to get from A to B without having to wait for a train for long. You just have to find the right way through the maze of connecting trains 2) trains are super punctual 3) fares are reasonable and predictable 4) when I do get lost (and inevitably I do) there are always helpful people around to send me to the right platform.

The only mistake I made - taking a Tokyo metropolitan train with all my luggage during rush hour. But then again, who would have thought that 10 pm on a week day would be peak time for office workers to go home.