A stupid person is the most dangerous type of person there is.
A person is stupid if they cause damage to another person or group of people without experiencing personal gain, or even worse causing damage to themselves in the process.
There is a tendency to underestimate the number of stupid people in the world.
The probability that a person is stupid is independent of any other characteristic possessed by that person.
Non-stupid people always underestimate the harmful potential of stupid people; they constantly forget that at any time anywhere, and in any circumstance, dealing with or associating with stupid people invariably constitutes a costly error.
I think a person may be "stupid" in some categories of life, while being insightful in others.
I may be stupid in social circumstances, but be very insightful with mechanical abilities.
On the flip-side, don't hire a politician to fix your car.