Do you always have spares or do you get them when you need them?

Do you spend the money, time, or effort to have something ready just in case you need it? Or do you wait until it is broken and then take care of the issue?
Here’s an example:
I was using my snowblower a couple of days ago and must have hit something large buried in the mountain of ice and snow at the end of my driveway. My snowblower has 6 augers in front, each attached with a ¼” shear pin that acts like fuses so it breaks instead of the driveshaft. One pin broke so one out of 5 augers stopped working rendering the machine inoperable. I had 2 spare shear pins on the shelf that I bought when I got the snowblower 8 years ago. I figured it would be a good idea to have them handy in case I broke one. It took about a minute to replace it and I was on my way again.
Knowing I only had one spare left I ordered 8 more. I also have a replacement belt just in case.
Thinking about it I realized I have spares for everything: cars, faucets, hoses, etc. I have spare oil filters and spark plugs for cars I don’t own anymore.
I do the same thing with heating my home. I have oil heat, and wood burners, and small electric heaters, just in case. I have 2 generators in case I lose power and one doesn’t work. I have 2 refrigerators and food in the pantry.
All this these spares cost money and take up space but they are invaluable if and when you need them.
At the other extreme there are people who have nothing in stock but have very neat, empty shelves.
I think there is a philosophy or personality type hidden in these actions.
So, do you have spares?