Think of it like human attraction. The looks are what everyone notices at first, but unless they have a good personality, that will only ever take things so far. At the same time, if someone has a great personality but is severely lacking in the looks department, they're going to have a hard time attracting someone.
Comics is a visual medium, so I won't lie and say the art isn't as important as the story. A lot of the time, it IS the story.
That being said, I think the right time to start something is usually now. I mean, we're not getting any younger.