We learn to endure to the end by learning to finish our current responsibilities, and we simply continue doing it all of our lives. We cannot expect to learn endurance in our later years if we have developed the habit of quitting when things get difficult now.
I'm in a serious monogamous relationship, and I don't want to keep having different boyfriends, and I have this instead - with men and women. It's better. Instead of having sex, we have art.