Former president Barack Obama brought his trademark humor to a White House ceremony unveiling his official portrait on Wednesday. “When people ask me what I miss most about the White House years, it is not Air Force One that I talk about — although I miss Air Force One,” Obama quipped as a room full of his former staffers laughed. Obama told his former staffers that he’s thankful to stay in touch with many of them and “thrilled” to see them start families of their own. He has one qualm, however.