In 1999, NASA lost a $125 million Mars spacecraft due to a simple math error.
The navigation team at the Jet Propulsion Laboratory used metric units of measurement (meters, newtons), while the engineering team at Lockheed Martin used the English system of measurements (feet, pounds).
Rather than slipping into a stable orbit over Mars, the mismatch in measurements led to the spacecraft burning up in orbit.
There are two lessons to take away here.
First, check your work. Pay attention to details and avoid making assumptions. Re-read that email and make another pass at editing that paper. Better yet, get someone else to do it for you.
Second, unless you too are a rocket scientist at NASA, don’t take your mistakes so seriously. Those two engineering teams set the screw-up bar extremely high back in 1999, so you’re unlikely to make a mistake that extraordinary in your lifetime.