Absolutely, because after a while this helps you internalise and see errors in other people's work, that everybody else is just letting flow past them. Even be

Absolutely, because after a while this helps you internalise and see errors in other people's work, that everybody else is just letting flow past them. Even being able to do simple arithmetic in your head to check for errors in slides/talks is a major step up. It will only take one moment of realising that the person talking has made a mistake in their calculation, and is basing their argument on that mistake, to realise the power of this - and that's just the simple stuff.