This anecdote seems suggestive!
But Wittgenstein was by all accounts deeply troubled. He was a tortured, misunderstood genius. 3 of his 4 elder brothers died by suicide, so you've got profound misery in circulation there.
He wrote expressly that he was not happy--that unhappiness was one of the great problems of his life. He had need of Epicurus:
"Vain are the words of that philosopher that do not relieve any human suffering."