We are planning a summer vacation. The big plans—flights, accommodation, transport—have been sorted out. What’s left is the smaller things: activities and meals, mostly. Trip planning is difficult. I know some people find joy in making the plans for upcoming travel; I am not one of them. Still, we plan. We plan because we want to have memorable experiences, to build memories that will last for years, moments that will leave indelible marks on our lives. Growing up, we didn’t go on man...