Albert Camus said this quote

Believe me, there is no such thing as great suffering, great regret, great memory... Everything is forgotten, even a great love. That's what's sad about life, and also what's wonderful about it. There is only a way of looking at things, a way that comes to you every once in a while. That's why it's good to have had love in your life after all, to have had an unhappy passion - it gives you an alibi for the vague despairs we all suffer from.