In this article he managed to calculate what a person should do to avoid becoming obsolete. Charette wrote: "Jones postulated that a typical undergraduate engineer invests approximately 40 hours per week of study over 120 weeks in his or her degree...Jones said that approximately 2,400 hours of undergraduate knowledge were likely substituted...a engineer should spend 5 hours each [week] acquiring new technologies, mathematical and scientific knowledge... to stay current." (Charette). This is where lifelong learning would come into play. Keeping your mind sharp and keeping up with tech “upskilling,” as it's called, is one way to ensure you don't come across as someone younger than you in the workplace. Engineering isn't the only profession that fears becoming obsolete; doctors, psychologists and even philosophers have this fear of becoming stale in their profession