What is a very special friend?

[Anonymous]

Guy friend called me a very special friend.
Background info:
a while back we had sex, we are close emotionally, talk and confide in each other all the time.
He also said he liked me for gazillion reasons.
Considering all the above, what does he mean when he says a very special friend?

Updates

+1 y

He also says he thinks about me all the time

[thevioletogre]

he thinks about you and cares about you. he might also be neglecting to tell you he loves you. emphasis on might. for a guy to open up in such a deep level it shows he feels he trusts and likes you very much. in short it is a friendship that he will never let go of even if he had to sacrifice something in return.

[mooky06]

Someone who he really cares about