Source: www.vba.asn.au
Next time your partner blunders, reflect on this conversation from Victor Mollo’s immortal Menagerie series.
The speaker is the Hideous Hog, the self-proclaimed best player in the Western Universe, and the Eastern as well:
“What does it feel like to make a mistake, H.H.?” asked Colin the Corgi, the facetious young man from Oxbridge.
“How would I know?” retorted the Hog indignantly.
“But surely, H.H.,” persisted the Corgi, “there must be bids and plays that you’ve regretted making?”
“Certainly,” agreed the Hog, “but that’s by no means the same thing.
Mistakes, you know, fall into very different categories. You may miscount trumps or not realise that the 
5 is master.
That’s merely due to lack of concentration, strain, fatigue, opting unwisely for the other half of the magnum at dinner.
I would call it a behavioural lapse, rather than a mistake.
Failing to spot an overtaking squeeze, that’s a mistake undoubtedly, but it doesn’t really apply for it’s a limitation imposed by nature, such as not singing like Caruso. It doesn’t make one feel guilty.