Notes:
Some minimum level of education is usually essential to finding and keeping a job. That minimum level of education continually increases. You can not expect to compete successfully in the job market without being able to read -- and learn on your own.
Most people will not be able to advance beyond a certain point unless they are able to write reasonably well. (My own experience in reviewing the writing of college graduates is that less than 1 out of 20 can write a reasonably readable three page memo. Even worse, the other 19 usually do not realize they cant write and therefore take no action to learn to write intelligently.)
YOU will compete for jobs in an entirely different market than did your grandfather.
My grandfather could look around the country school he attended and see his competitors for jobs.My fathers competition for jobs lived in Central Iowa.By the time I graduated from college, my competitors for jobs came from all parts of the United States.YOUR competitors for jobs come from all over the world. -- Regardless of how simple or complex the job.