Forgive and forget

For long this has been one of my favourite debate topics..
I have always considered 'forgive and forget' to be an atomic transaction - that without forgiving, there is no forgetting, and more so vice versa!
So when people say - forgive, but never forget, it seems really difficult for me to do.
If you don't forget about what happened, your future actions will always be conditioned by experiences of the past. Those incidents will always be at the back of your mind, and even a slightest misunderstanding in the future will bring those memories flooding back to your agitated mind.
Well then how do you make sure you have really forgotten all the bitterness, and that you truly have forgiven? For me talking it out with the concerned person has always worked.
There was a phase a couple of years back, when I thought I had completely lost the ability to talk it out, forgive and forget. That is when I realized the importance of talking things out at the right time and of never going to bed angry with your near and dear ones!
I also learnt how difficult it is to take the first step in such cases, and how difficult it is to meet people who you can take the first step for, with no hesitation at all!
Why does it get more and more difficult with age? I dont recollect having any such issues as a kid. Is it ego? Or is it fear of being hurt again? Or maybe a combination of the two?
But the fact remains that with some people you are always a kid, and with them such issues never come up. Maybe you can strike such a chord with fewer and fewer new people in your life, but with the old ones, the relation is as fresh and tension-free as a new one :) These are people with whom the condescending step of 'forgiving' never comes up.. And those relationships make up for all your other relationship blunders, and make you love the beauty of having close friends!