If we want to ride an aeroplane, we have to know who is piloting the plane. If we are being told that the one flying the aeroplane has over 40 years of experience in riding a bike, with little to no knowledge of flying the aeroplane, we would never trust the person to fly the aeroplane. Because riding a bike and piloting an aeroplane are very different.
Therefore, we must look and consider from whom we are taking our knowledge.