Your ego is the part of you that tries to protect your self. It is the facade that you present to others.
Your ego is the part of you that takes offense. It does this to try to protect your real self from attacks.
Your ego, though it tries to help, can be quite unhelpful. It would rather make you completely miserable than allow you to admit you are wrong. It would rather make you completely lonely than allow you to open up and thus risk being hurt by someone.
Since your ego is a facade, it is, by definition, a lie. So it is not effective against truly perceptive people. And, more importantly, it trades happiness for perceived safety. That's a bad trade because safety is worthless without happiness. Safety is supposed to enable happiness, not stifle it.
In order to be happy, you must let your ego die. [1] It is painful, and if you're like me you may have to experience that death many times. Remember that gaining happiness by losing your ego is a good deal. And the alternative is to lose happiness by keeping your ego.
[1] Matthew 10:39