Falling asleep while standing

There are several occurrences that I struggle from falling asleep while standing. Yes, it happened to me several times. During my internship 11 years ago, there was once that I almost hit a metal rack because I almost fell asleep. As for now, thankfully it does not happen at work. But there are several times when my wife needed to watch me from falling as I was half asleep while standing in the train. 

During those period, somehow I could not hold my sleepiness. I was just sleepy that my own control of the body is reduced. Well, I may not fully control this kind of thing from occurring. But at least there are several things I need to do to reduce its probability: sleep enough every day, take action when feeling sleepy - whether to take a short nap or to drink coffee instead of doing nothing, and to manage eating - not to eat too much that the blood flow is not normal. 

Likewise, in life, we need to be aware that we can fall even when we look like standing tall. We need to watch out and establish good habit so that we can be fresh and ready instead of losing the control on ourselves. In addition, when there is a problem, we need to decide quickly on what to do including waiting instead of not making decision and be torn apart from the different possible options.