Blatantly stealing from the excellent post by /u/judah, I figured I'd make a sysadmin version because sysadmins tend to be underrepresented in tech discussions. Please keep your answers as cross-platform as possible without being uselessly generic.
I'll start. Realize that the system is going to go down, and accept that reality. Accept failure. How you respond to failure is how people who aren't sysadmins will see and value you.