One of the things that appears to separate us from the rest of the animal kingdom is our ability to know we are thinking, what is known as meta-cognition.
Connected to this meta-cognitive ability is our capacity for reflecting on things that have happened. This ability to remember at will, and in effect go over things again, lie at the heart of one of our learning systems. Because we can go back and 're-live' a situation, we can also come to conclusions about an event and then plan what to do the next time something like this event occurs again. So image you have just had a conversation with the boss about a job he or she gave you and the boss got angry during the conversation. Under normal circumstances when we are well balanced and have things in perspective we should be able to go over the events again and work out what went wrong, even to the extent to realising that maybe we should have handled things a bit differently and it's not surprising the boss got angry, or what ever conclusion we come to.
This ability to reflect on things is a vital part of our reflexive learning processes (exploring the relationships between cause and effect). If you reflect, come to a conclusion and make a plan, and maybe even put it into action, you have engaged in learning.
This is normal and you will move on. What can occur for many people however is that they get stuck in a cycle between reflecting on what happened, or worse still on what hasn't but could happen (a projection) and coming to a conclusion. So the individual goes from reflection, to conclusion to reflection and so on, without breaking out of the reflective process and never reaching a final conclusion. This can occur in some individuals many many times where they find it hard to let go of the reflective phase of the process. This rumination particularly occurs when there are negative emotions present in the scenario and is the hallmark of depression and episodes of anxiety.
So given the situation above, the individual would keep coming back to the conversation with the boss in their head and start to feel the uncomfortable feelings of embarrassment, anger, anxiety or whatever. The emotion then blocks the progression of thinking (to conclusion) and the individual goes back to reflection and so starts another (vicious) cycle of reflection or rumination.
The problem with rumination is that every cycle of reflection can intensify the negative emotion and make the next cycle of reflection even more likely and emotionally worse.
These ruminative traps are more likely when we are feeling anxious, depressed or even stressed. OCD is also based on this process, but has become more of a habit or trait for the individual. Rumination keeps us stuck in the emotion.
Like the conclusion of my blog yesterday, going and doing/focussing on something else is the way out of this cycle, and getting some help from stress, depression or anxiety of course.