[zepto]

> But people are notoriously terrible at estimating their own productivity and how they spend their time.

That’s true.

> Almost everyone I know who has tried time tracking and life logging is shocked at how different their expectations are from the reality (mostly that they do less and work less than they think).

Right, and time tracking and life logging are now widespread practices, so people who do these things can do a pretty good job of estimating their productivity. Also we have things like the Pomodoro method, commit histories, etc. to give indications.

I completely agree that guessing your own productivity difference without doing anything to measure it will not yield good data.

Now look at what the GP is doing - they are using an anecdote of one person’s productivity to make a claim about the productivity of a wide range of people.

My point is that their experience is very unlikely to give them the data and insight needed to make such a generalization because they aren’t measuring anyone’s productivity - they are just using an anecdote.