How to understnd the one you care for?

People always comment others on first impression when they meet a new guy.
After days passed by, they may concern about the level that others understand them?
Also, what level they understand others?
This period, I am thinking about this issue. So, I asked some good friends. Among them, Mr. Pig told me that he is fully understand me. I laughed his comment, and, I am so happy to hear it.
Besides, Mr. E told me that he can't catch my thoughts. I am confused as I feel he is the one who can understand me. Thus, I think I should open my mind and face my truly feelings.
In short, I will try to share it with my goods friends because I think to be understand is very important.