Nine years ago, I lived in BMW’s housing for interns. We were all on a budget, and so one day, my neighbor suggested we make sandwiches. He had a panini grill and, in just a few minutes, with nothing more than salami, cheese, and oregano, he whipped up some surprisingly good toasts.

From that day onwards, we ate sandwiches at least three times a week. We made salami sandwiches, tomato sandwiches, and cheese sandwiches. We invited the entire floor to join. It was cheap, fast, and delicious — and it became a defining memory of that period of my life.

Naturally, I bought a panini grill shortly thereafter, and today, nine years later, I still regularly make sandwiches. Same recipe. Same device. And it’s still cheap, fast, and delicious.

Some things really last forever. You never know behind which door lies a lifetime favorite recipe, a lifelong friendship, or an object you’ll carry with you till the end. But every day, you do open doors. Pay attention and, every now and then, remember to cherish the habits carrying you a great deal of the way.