Not to be advanced then its true that there's no such or no one does know on what the future holds but if you've been thinking about separation or getting divorced then its better not to become married at all. Love does have no boundaries on which if you do love a certain person then loyalty and pouring all the love that you do have to him/her would be always that common act. Be dubtious or having that advanced thinking will really be putting you on anxiety and being worried for the rest of your life which i could consider to be a toxic kind of assumptions.
Everyone thinks what they want. For example, you know you're going to die one day, but that's not why you live in anguish. When you make a will, it's not because you're going to die, but because you're making sure that everything goes smoothly (especially if your heirs don't get along).
When you buy bitcoins, you also know that the price may fall or that you may be hacked, but you're not going to spend your life stressing either.
You marry for love, but over time everyone changes and sometimes you get divorced. Some people even end up hating each other and doing the worst things to each other. It's better to think about it now, rather than be ruined afterwards, thinking "Gee, I never imagined it could end like this".
And there's no point in saying it only happens to other people and I'm going to live happily ever after with my wife. Nobody knows what can happen.