An average learner anyways can't retain majority of the information that is transferred during a classroom training session, and on top of it, when the
time comes a learner may not be able to put that
knowledge to use
due to frequent changes
in job requirements or because that information is no longer available
in an easy to use form.
When such a
time comes, plenty of arcades are unable to repair machines
due to either a lack of replacement parts, or lack of
knowledge in repairs.