It's absurd to say you can forget everything all at once. You do it with every moment you are currently experiencing. You do it at night when you refuse to gather thoughts from the past and do it the day, when you accept her life and her beauty. You will remember what you loved and you really lived - that's normal. And it's normal to keep what's causing you beautiful emotions. The rest detach yourself, give up and forget.
Do you want to be happy? Forget! And when you remember, forget again. - quoted with anonymous author