Mean reversion is the theory that price action will inevitably move towards its mean or average. In many ways this is a self-fulfilling prophecy: we are adding to and forming the average simply by transacting at prices close to the average, we will never buy or sell too far away from the current price! As the price action moves further away (divergence) from the three types of moving averages : simple, weighted and exponential, there is a higher probability the price will revert back to the mean or the mean will move towards the price action (convergence).
The quick lesson here is on any chart and on any timeframe please use the 20SMA, 50SMA, 200SMA, VWAP and at least 1 EMA indicator. These lines are powerful because prices are moving towards these moving averages meaning buyers and sellers are transacting the most here (known as areas of dynamic support and resistance). When these lines cross each other momentum, sentiment and even mood is changing.
Think about it for one moment, people are mean reverting are we not? Similar to price action, we appear random and spontaneous at times. But, the truth is for the most part we are a reflection of ourselves. No matter how far we deviate from ourselves, we eventually become who we are always meant to be.
The only time we are not mean reverting and not acting like ourselves is when we have decided to do something profound enough to change our way of thinking. Think about it, what are you willing to do so from now on you are going to be profitable and look back at the mean from outer space? Yes, look back at your poor self now from a private jet. After all, mean reversion is only a theory not a principle or law.