self-reflection

When I recall his reaction, I feel that I was like him before in a sudden.People who beside us are always the mirrors that reflect our shorts. Do not be so full of ourselves, we are not always right.

I'm native, but not a teacher, so there may be better corrections.  This is how I would write it: 

When I recall his reaction I feel that I was like he was before, in a way.  People who are close to us are always the mirrors that reflect our own shortcomings.  We should not be so full of ourselves, we are not always right.

Nice work!