You’re not always going to have great training days. Life is filled with distractions, and you’re going to get stressed out. Combine that with a bad night’s sleep or a lack of food, overtraining and you’re looking at a lot of things that can potentially go wrong. The bottom line here is that you’re not going to have great days all the time. Everybody has less than stellar days, in fact if you train very hard, your probably going to have more bad than good especially mentally.