Fairly sure Mark's point still stands. If he survived by running and hiding, after 30,000 years he's the best darn sneak thief ever (if he wasn't, he'd be dead). Even if Joe the mediocre accountant from the modern era time traveled back to the Roman Era, he would still be powerful. As the old adage goes, knowledge is power; Joe here would know of many, many things the Romans couldn't even conceive of.
Power isn't strictly defined as raw strength or magic, since wealth, cunning, charisma, and ideas are all tremendously effective if used in the right way.