Life is full of memories. I think forgetfulness is one of the greatest gifts which we have received from Almighty. Though we all wish to be able to have a sharp memory and be able to remember everything, but I truly believe what I stated above. Because of this forgetfulness only, we can say that "Time is a great healer". Numerous events occur in our lives which we really do not want to remember, in such situations this forgetful nature of ours really helps us a lot. If we would have been able to remember everything always; this world would have been a difficult place to live in. I think in that case these psychiatrists could have made cool money (well, they still are making :)).
Every bad accident, bad event, bad experience, bad relation, anxiety, tragedy you had would have stayed in your memory and would have haunted you whenever you may attempt to take some steps to overcome the burden and move on. Life itself really would have been tragic. Loss of a person, a family member, a closed one shatters us completely and fills us with anxiety and pain. But still we are able to overcome that because of this forgetfulness. Of course the time taken by a person to overcome varies from individual to individual but ultimately we are able to move on as we say "Life moves on" .
I thank Him for this quality (of forgetfulness) but at the same time I wish we could keep all the good memories we had; at some different partition of brain (or something like that), so that we may always remember and cherish the good moments we experienced, may it be for a few seconds or many days together. Anyways, these whims and fancies we have can never have an end. Lets be happy with what we have at least whenever something goes wrong; we can be sure that someday, sometime "Life will move on" and everything will be fine.