What are some habits you started during some life-changing event, that you've retained still, long after that event has passed?

From having kids:
I still put my sharp knives blade down against the wall of the drawer.
I still keep my cleaning products up high, out of reach.

From being poor:
I still wash and recycle aluminum foil for reuse.
I still only tear off exactly how much I need to cover a potato for baking (if you lay the potato long ways on the strip, you can cover it with a lot less foil than if you start at one end and “roll” the potato. I remember going to my Dad’s, out of state, and his wife served baked potatoes. I was shocked and aghast at how much foil she used on each one! Must have unrolled 4 layers of foil!)
I still wash and recycle zip lock food bags.
I don’t use paper towels for clean up. I use wash clothes.
I still save the wrapping paper that comes on Christmas presents, if possible, for reuse.