The train comes to a halt and you are awoken by the gentle jerk. It has been 15 minutes since this walk in heaven has commenced and you just want to keep walking. You look around - the train is still crowded, the people are the same, MP3ing or just staring at no one. Your walk in heaven can resume. The train starts, you close your eyes and you are walking again.
10 minutes later, your walk in heaven ends - it's time to walk home. You get out of the train feeling a lot lighter - in body, in mind, and more noticeably, in cash.