Lawyers tell their clients this right before they, the client, is deposed. As another commentor here hinted at, when being deposed you are either going to play it safe or lose, there is really no winning. Deposition hiccups are later used, at trial or in settlement negotiations, as leverage against your opponent or to try to discredit them as a witness/simply make them look stupid as a witness. A deponent seldom has anything to gain from waxing poetic about whatever they are being deposed about.

That's the litigation game.

Edit: spelling.

Not sure if it's taught anywhere per se, but in many arenas it becomes habit. "Do you know what time it is?" "Yes." "Can you tell me the time?" "Yes." "What time is it?" "11:30".

Why cough up the answer so soon? Make them specify the time zone.

And that they are asking for the current time. Not the time of the lunch break.

If you work for a "normal" company, your company's lawyer will spend a day or so prepping you for deposition before the actual thing.

And the deposition is very tiring.