It is strange how sad memories come back, suddenly. Sometimes, when you do not want them to. They claw at your heart, rip apart your mind and leave you exhausted, suffocating, desperately trying to hold on to something positive.
You try your best to be optimistic about a lot of things happening in your life, however, not always do you succeed. Despite following the 'be happy' mantra in your life; despite trying to be optimistic, there are moments when you cannot help yourself, moments when you unwillingly give in to the negative thoughts. You take the dive, you think you are swimming but then you find yourself drowning in sadness, the pessimism that fills your mind makes you want to shout for help. You look around, trying to find a log to cling on to; that one happy memory which will not only neutralise the negativity but make you optimistic about life, again.
We all need to keep logs in the backyard of our mind; if we want to be saved from drowning in sad memories which assault our mind without our knowledge. We need to keep happy memories handy, so that when we are engulfed in darkness of sad times, we can light the candle of happy memories on purpose and get rid of the darkness.
This is a process you need to work on actively. It is not something your sub-conscious mind will do on its own. You need to be at least that much aware of your own mental status as to intervene at the right time and bring yourself out.
When people say that you need to get rid of bad memories, when people say that you must not allow them to come and haunt you, they are asking for the impossible. They know it themselves, because even they have their own ghosts of the past. Memories do not leave you. Memories always stay. How you deal with them is what decides how well you are able to cope up with your past.
Memories will come back, they are meant to. Memories will haunt you, make you sad, make you cry and wonder why did things go wrong. Memories would make you go through the emotions again. You are human, you will have no control over memories so powerful as to shake your roots of existence. Be all that. Be sad, cry, wonder - relive the emotions, it is part of the process. Take the dive but do not allow yourself to drown - look out for 'the log' and grab it. Save yourself from drowning. Swim along, come back to the shore - hold on to the log till you are sure you are safe enough.
There is no way to get rid of memories; but you can neutralise the sad ones with happy ones.