Rumination is all very well but only if there is a purpose to it. I Purposeful rumination, where you go over events in your head, working out what went well and what didn’t and acknowledging what you could change next time you are in the same situation, is productive. Rumination which engages your Critical Parent (that nagging, critical voice in your head) is pointless and engenders guilt, which is also pointless unless it spurs you into changing things for the better. However, I suggest that in order to start tackling our mistakes effectively, we need to be kind to ourselves. In this way we become optimistic about our chances for success and raise our self-confidence rather than becoming despondent and giving up.
Going over an over an event that has already passed and blaming yourself for the outcome is an exhausting, self-punishing exercise with very little purpose. Calling yourself stupid, or an idiot undermines you and has poor consequences for your next encounter where similar issues arise. A much better idea is to engage your Adult thoughts and analyse what went wrong (if it did) how you could have avoided what happened (and maybe you couldn’t). Then review the situation and recognise what you would like to change about your responses and behaviour. Remember you cannot change other people’s behaviour but taking responsibility for your own may cause them to respond differently to you. A good question to ask is “What happened?” “How can I get a different and preferable outcome next time?”
If you are someone who has a large internal Critical Parent then be kind to yourself and start to use phrases such as “I did my best but I forgot to ask the right questions.” Or “Given my level of experience I did OK.” Doing OK is absolutely fine. We cannot always be expected to perform to our very best, particularly in unfamiliar or scary situations. Try to talk to yourself as if you were a child of 6 or 7 or as if you were talking to your best friend. Would you call them an idiot and go on and on about past mistakes - unlikely; so don’t do this to yourself. Instead, be kind, ask for help if you need it and recognise that your old, scolding voice is unproductive and detrimental to success. With time and effort you can change an internal Critical Parent into a supportive Nurturing Parent who can support and sustain you and eliminate pointless, undermining, guilt trips.