Back in the aughts, actor and former jeans model Jack Scalia set up charities to benefit both 9/11 victims and military vets. The charities raised some money, but apparently distributed less than they received. Where did all the money go? Scalia doesn't know—he was busy.
It's true that biking requires focus, especially given the dangers cyclists face whilst on the road. But some people—for example, select IRS agents—seem to believe that such concentration must be redirected to other things whenever one dismounts from one's bicycle. Otherwise, they get upset with you.
Though imperfect, Scalia's excuse convinces us—but maybe because we're overwhelmed by his enduring handsomeness, or sympathetic to two-wheeled types. It does seems useful for explaining away ignorance related to other types of situations: For example, students who don't know where their homework is might try telling their teachers, "I was riding my bike ... I don't know that end of it." If their teachers still assign homework, that is.