Trading can be really stressful and time demanding. Any minute you stay out of the system can cost you serious damage. I trade only when I have all the time to sit by the system.
As soon as I move away from the computer for a long time (half a day, day), I certainly miss the good price. It kills me. Instead of 10% profit per day, I have 1-2% or even a minus. Yes, I don't have a strategy, but I try to learn all the time.