Learning at work

What’s something you can only learn at work?

I’m lucky that most of what I learn at work are things I’d want to learn outside of work. I work with code, algorithms, designs, and I enjoy it so much I’d probably do it even if I didn’t have to get paid for it. On the other hand there are things I’m forced to learn at work that I would probably avoid if I wasn’t working. I’m thinking of things like planning and strategizing, building a business, working with and learning from customers. I certainly see value in these things, but they are about building a business, so you can only really learn them on the job.