Never take advice from electrons. They are always negative.

Behind the Groan

The Electron's Negative Charge

Electrons are subatomic particles with a negative electric charge. In everyday conversation, a negative person expects bad outcomes or discourages ideas, making that person an unhelpful source of advice. The punchline applies both meanings to the electron. Read the warning seriously, then give “always negative” a small pause. Basic science knowledge supplies the second meaning without further explanation.