The Moment: what happened
It was my first month at the IT firm. I was configuring a network switch, following the design doc. I finished fast, and felt good about it.
My colleague Yakov had fifteen years in the field and zero patience for bullshit. He pulled up my config and scanned it line by line.
"This port. What happens if someone plugs a rogue device in here?"
I looked at it. Shit. No port security.
"They could access the network."
"Right." He wasn't mad. Just teaching. "Why'd you skip it?"
"I don't know. It seemed right."
"Seemed right?" He turned to face me. "This is production network. Seem right is how you cause outage at 2 AM."
Then came the line that rewired my brain: "You want to be good at this? Stop guessing. Know why."
The Moral: why it matters
You know the pattern: The presentation you deliver but can't defend when someone asks a hard question. The strategy that sounds smart until a skeptic pokes a hole in it. The decision you made because it felt right, and then you can't explain your reasoning when it matters.
Confident and competent aren't the same thing. One feels good. The other holds up under pressure.
The Move: what to do about it
Pressure-test your own thinking before someone else does. Can you explain why this works, not just that it works?
If you can't, you're guessing. And guessing is how you cause outages at 2 AM.
Gut Check: What feels solid until you try to explain it out loud?
— John Grover