Obama jokes with ABC's Charlie Gibson when asked about his youthfulness. "Well, in order to deal with the first problem, that I'm very young, I'm cropping a lot of gray hair over the last year and a half," the told the anchor in an interview for "World News."
More seriously, he adds, "But there is no doubt that as somebody who has not been in the national political scene as long as John McCain, that people are going to have more questions, and I think that's perfectly appropriate."
Obama also said, "The main purpose of the trip from my perspective is looking at some of the most critical issues that the next president is going to have to deal with and developing some relationships that I think might be useful in solving some of those problems."
Watch the video here.