Ain't that the truth, Dave! No staying power... But particularly they're usually too selfish, so don't get the concept of 'give and take'/compromise, and just cry 'divorce' as soon as the going gets tough or they don't get their own way. Plus, I've been brought up in a family with numerous successful, long-term marriages, so for me it's the norm
Hope your good lady and you have a nice 50th, and I wish you long and happy/healthy life together, and so many more anniversaries!
Marco.