Memories seem to be what make us the people we are. Without the who, what, when, and where of our every day lives we would have a difficult time functioning. With our short term memories we are able to mull over the various options we are presented with and able to make informed decisions. Without being able to make decisions almost constantly throughout our days, we would find ourselves at a standstill.
The past memories we store in our souls make us the people we are. Without them we become flat and have no frame of reference. Our lives become sad because "now" is all there is.
Thank God for your memories and pray that they never leave you - even the bad ones (may they fade though). Memories are a terrible thing to lose.