In my case, which is probably typical, there was a bug in a device driver for some obscure thing we were using where I worked. So I had to dive into the world o

In my case, which is probably typical, there was a bug in a device driver for some obscure thing we were using where I worked. So I had to dive into the world of kernel modules and fix it. I think a lot of kernel knowledge and development is commercially-driven, in this sense.