I'm only 40 and I'd have a hard time giving specific years for many of my major life events including:
When my nan died
When my grandpa died
When I graduated HS
When I got my bachelor's degree
What year I left my last job
Like, these dates don't really hold the kind of relevance of the events themselves. I can't imagine how hazy those dates will be when Im 70+.
Anyway, I'm not sure the job of president is to remember specific dates from your resume.