The Sysadmin Breviary

When the headphones are on, I am unavailable. I only put them on for a deployment, a migration, or something critical.
Zen mode is life.
"We don't always test new features, but when we do... rest assured, we do it in production."
Documentation is like sex: when it is good, it is very good; when it is bad, it is still better than nothing.
It is always DNS.
Friday is read-only. Learn it. Know it. Live it. No changes get made on a Friday. Period.
The company wanted to exhaust the office furniture budget. Buying thirty mechanical keyboards got approved. It is an open-plan office. You have no idea how much joy that petty little prank brought me.
Always use Velcro. Never zip ties.

When troubleshooting a strange or unfamiliar issue, always start at Layer 0. Check the physical connection - in person, if possible - and work your way up from there.
Make sure the server actually responds to ping before you start troubleshooting and crawl down a rabbit hole.
Pinging the broadcast address populates the ARP table.
Turning it off and on again actually helps in far too many cases.
Trust users, but always verify.

HR is not your friend (nor your enemy), and your company is not your family.
Set clear boundaries and avoid setting a precedent of being on-call 24/7. Your personal life belongs to you, and so does your mental health.
Learning how to use a search engine effectively is absolutely critical.
It is okay not to know something, but put in the effort to figure it out and understand it. Our work is a state of perpetual learning.