Bruce Duffy, The World as I Found It (pp. 116-117, NYRB edition):
Wittgenstein continued. I eat simply. Vegetables, mainly. Meat disagrees with my digestion.
A misstep, this; his mother carefully daubed her lips with her napkin, leaving it to his father to ask, There is something wrong with your digestion?
Wittgenstein waited three beats, then replied, Not if I eat as I should.
And the food here? asked his father pointedly. It is too rich for your digestion?
A pleasant change, replied the son agreeably, though he felt his smile curdle.
Resumed his father helpfully, A change before you go back to your bland fare, you mean – so you will know the difference. Barbishly, his father then quipped for the benefit of the table, Ever the philosopher – our latter-day Epictetus. Then, seeing his son’s withholding look, Karl Wittgenstein asked, You have not read the Stoics?
Wittgenstein froze, as if it were natural to expect that, as a student of philosophy, he must be conversant with every facet of the subject. Gathering his forces, Wittgenstein replied, I understand the basic outlines of the Stoic creed. That is enough.
His father stared at him. They don’t teach the Stoics at Cambridge? he asked, as if to say, The English are so debased?
They teach the Stoics, replied the son patiently. If one is reading philosophy in the Tripos or studying the classics. But that is not what I’m about.