Splitting up after 40 years

I just heard the news of Al and Tipper Gore splitting up after 40 years together. Without commenting on their specific situation (since I don't personally know them, I can't know the reasons behind), I just have to say that the news made me sad. That is a long time to share with someone, and I am sure there is a lot of ups and downs, happy and sad times in those 40 years. The cynic in me wants to say that I am sure we will read about the reasons for the separation in their upcoming books... But despite the cynicism, I am still sad for them.