I have been a software engineer for 25 years and an engineering manager for 6. I know how to build things. What I could never figure out was how to remember everything I built, reviewed, commented on, or responded to on any given day.
My calendar tracked meetings fine. Everything else just disappeared. PR reviews, Jira comments, ad hoc requests from leadership, performance review prep, one-off conversations that turned into two hours of unplanned architecture discussions. By Friday I could barely reconstruct Tuesday. I eventually started keeping a running Google doc of everything I touched each day, including meetings. It was exactly as tedious as it sounds.