I did an overnight bus ride around Myanmar and did a border crossing from Bangkok, Thailand to Siem Reap, Cambodia (roundtrip). Oh, and I also tried the overnight bus from Tokyo to Osaka (roundtrip). It's not always comfortable to sleep on the bus but I can always fall asleep. And I was doing a solo trip before, so, I needed to find a friend or always talk to the ticket guy so that they wouldn't lose me. Thankfully, a few locals in Myanmar were very helpful in being sure I made it to my destination.