Careless Mistakes.

Careless mistakes are defined as unexpected, unintentional and simple to make errors.

Careless mistakes don't matter as much as we think because we are always capable of them, we will always make them, we cannot prevent ourselves entirely from making them, and in the long run we'll unavoidably make plenty.

Without careless mistakes, I would have got perfect scores every single time. I have concluded that careless mistakes are random errors that reduce precision, but never accuracy. They still follow an approximated normal distribution. Accuracy always matters far more than precision (both matter but not the same), and if it isn't, it just means you need a better algorithm/computer to do the arithmetic or calculations.

Careless mistakes are the most intelligent bugs there are. While they may disappear from a certain piece of code, they can always hide in you. They run away or teleport away when you detect them, but there's always somewhere they would hide. We should not be annoyed at them, but instead calibrate accordingly. We should always allow ourselves the time to calibrate for them (also called testing and debugging), instead of forcing ourselves as human beings into situations without chance of correction.

The smarter you are, the smarter your bugs are. But it is always possible to remove bugs from a particular piece of code because we always tend to know what we want the program to do, but we can never quite pin down EXACTLY what we want, because we are not exactly defined ourselves.