Here's the thing; You can never be sure of the things you don't know. Your opponent may have something up their sleeve that you didn't see coming, no matter how weak they appear. By assuming your opponent could beat you, you are better able to objectively think about all of the many ways in which they could potentially trump your argument or battle strategy, and prepare for those situations, no matter how unlikely they seem.
Much of the information (or training, if you are in sports/battle) you must gather before you face your opponent will never be used, but knowing what to do in the event that you are challenged where you are weakest gives you the best shot at winning in a worst-case scenareo. Never assume you have won until it's over, and you will have the best shot of doing so. If you underestimate your opponent, you give them the opportunity to see something you do not, and attack you in a way you are not prepared to defend yourself against.
A cold war.
World War 2 taught (some) Americans that we need to be more tolerant of different races. When they heard the horror of the Holocaust, they realised that we were also intolerant of African-Americans as they were of the Jewish population.
Lincoln's opponent in the 1860 election
In the U.S., there are things that you must never do with an American flag. The flag must always be lighted, either by sunlight or artificial light. The flag should never be dipped to any thing or any person. You should never use the flag as a form of advertisement.
relocation should never be performed cuz it screws college kids up
Never ever underestimate your opponent!
Don't underestimate Your Enemy,Don't underestimate the Enemy, orDon't underestimate Enemies, or Don'tunderestimate your opponent
Never underestimate a child.
Never Underestimate the Power of a Woman was created in 1981.
The candidate was less well known than his opponent. You should never underestimate your opponent in chess.
Many people underestimate the impact of regular exercise on overall health and well-being.
ducks and pigeons
This saying emphasizes the strength and influence of an individual woman. It serves as a reminder not to underestimate her capabilities, determination, and ability to make a significant impact.
never underestimate the importance of you
never underestimate pussy eaters
never give up on women
Never Underestimate Radical Vision