If I go to Wal*Mart or Tesco or wherever and get a job I will be trained for 90% of the store within a half-hour orientation session. It requires minimal thought, and in most cases action, on my part. If I go to university I will be trained for a specialised area of medicine within 7 years of tutoring. It requires immense expertise and knowledge to even diagnose things, nevermind take action for them, on my part.
More to the point, you can live without going to Wal*Mart.