Divorce Immunity

I was listening to a podcast this morning about a family who experienced so much happiness together, and for certain reasons that are irrelevant to this post, the parents eventually got divorced. The parents continued having a very amicable relationship, but I was still saddened by the divorce. I was saddened because of why they divorced, just that they did, and it made me think about how unbearable it would be for me right now if Mary approached me and wanted a divorce. A divorce is unfathomable to me giving the state of our marriage currently.

But I was left wondering something. Do couples who divorce after 25 or 30 or 50 years feel the same way at 11 years of marriage as I do now? When they had been married for 11 years, was their married life blissful and divorce unfathomable? Or has the reality of eventual divorce already entered into their marriage by that point? Can I be realistic that if my marriage is as strong as it is now at 11 years, that it will always be immune to divorce?