Hard to say, either he thinks nothing of it or he's hiding something. If you want to find out you could set up a fake account and add him as a friend to see his page if its set as a private profile.
Is he at all shady in any way that would lead you to believe he's hiding something? Have you met most of his friends/family?
So, so you think you can tell Heaven from Hell,
blue skies from pain.
Can you tell a green field from a cold steel rail?
A smile from a veil?
Do you think you can tell?
And did they get you to trade your heroes for ghosts?
Hot ashes for trees?
Hot air for a cool breeze?
Cold comfort for change?
And did you exchange a walk on part in the war for a lead role in a cage?