Rehearsing/repeating information is a good way to improve your memory. Mnemonics such as ROYGBIV (Richard Of York Gave Battle In Vain) to help remember lists can be useful. ROYGBIV is used to recall the order of the colours of the spectrum.
AnswerNew bad memories replace old ones, so then the old ones are still there but don't hurt as much. Answer I think that facing the memories is what you need to do. Do not be affected by them...