The difference between "people at their best" and "personal best": https://www.bbc.com/news/articles/cj0v632yddzo
Last year, I trained hard to go sub-3. I know the hours, the years, De Oliveira & Beggs would have put in to have the once-in-a-lifetime experience to run Boston faster than they'd ever run before - and the intensity of the focus on the finish line when it finally approached.






