Underestimation

Underestimating anybody in life is the most grave mistake one can do in his life and after that he is bound to fail in any "battle" against the other person. Once we have underestimated our opponent we tend to overlook their strengths and focus on their supposed weakness and then when the opponent hits we are not prepared and it spells doom for us.
I have always tried to avoid this mistake but belonging to the Human species I time and again fall into this trap and then when I discover their strengths I am totally overwhelmed. This has happened to me over and over again and it happened this week too. As people would say history repeats. When will I learn to remember my learnings?
Ok, I can sense the question as to who my opponent is. Here, I am slightly twisted the meaning of the word "Opponent". Here it means any person other than me. Why do I say this? Consider any professional environment. Here all your colleagues are vying for the same laurels that you are trying for too. So in some respects they are opponents, NOT enemies. You can be opponents and still be the best of friends. We deviated here but the explanation was necessary.
So the bottom line is the cost of underestimation is defeat and nothing else. The other way to look at this is everybody has some or the other strong, special trait and we should be ready to learn from them thus acknowledging their expertise in that field.