Curiosities

What is the most common jobs/careers/positions that you encounter every day that you don’t typically notice or think about, but upon further review, can’t think of how life would function without it?

For me, it is the mailman/woman. I never stop to think about it, but they come around almost every day, they are a huge part of our history, and have been the longest running system/organization of communication. They make mistakes like any other organization, but society as we know it can’t really fully function without them.