Professions are here for a reason

Thanks to Ivan Pepelnjak for the below one.
And many others as welll!

An unused knob is sometimes better than a used.

Professions are here for a reason – they enable people to do the work they’re qualified to do.

Needless to say, it took him decades to fully understand its implications.
Do what you’re qualified to do. Don’t think you’re good as me at everything just because you can Google-and-paste. Figure out where your limitations are.
Seek help when you’re dealing with something beyond your comfort zone. The amount of ignorant improvisation we see in IT is stupefying. Have you ever wondered why lawyers and doctors ask for second opinion?
Yes, I know your manager expects you to know everything just because you have administrator or engineer in your job title, which just proves he never thought about the next two paragraphs.
Don’t think you understand other people’s job. I’m always amazed to watch people completely unqualified to have an opinion on a problem loudly offering it just because they’re experts in totally unrelated field. PhDs in chemistry telling IT engineers how to do their jobs would be one of my first-hand experiences.
Don’t think you could do their jobs better than they do… until you tried and proved you can succeed while facing the same constraints they have. My favorite one: an airline pilot confident he could write a program to do airline’s crew scheduling (which is probably an NP-hard problem) on Commodore-64.
Having said all that, do your job well if you want to earn and retain the trust of your peers. If you’re obviously clueless or randomly throwing fixes at the problem trying to figure out which one might stick don’t be surprised when everyone else starts acting in ways I described above.
Accept help (courtesy of Chris Young).  When a grey-beard gives you a piece of advice - LISTEN. Doesn’t mean you have to accept it as truth or obey their commands, but watching people new to the profession make the same mistakes we all made 20 years ago because they didn’t heed the warning is frustrating…
And “I told you so” doesn’t fix the network or the harm that major network outages cause to our reputation as a profession.