Is Linux hard to learn?

If we take Linux kernel then it’s easy as compared windows and mac kernel but when it’s come the Linux distribution part yes it is difficult then windows os and mac os, There is no one Linux os it has many distributions like CentOS, Debian, Ubuntu, OpenSUSE, Mint, Slackware, and Gentoo Each distribution has its own configuration and apps so learning one won’t help you to master all so it’s difficult