When planning a visit from Bonn, where he was immersed in studying physics, his fellow mathematician and friend Hermann Minkowski joked he had to spend 10 days in quarantine before being able to visit Hilbert.
Cando planeaba facer unha visita a Bonn, onde estaba inmerso no estudo da física, o seu amigo e colega matemático Hermann Minkowski facía chistes dicindo que tiña que pasar 10 días en corentena antes de poder visitar a Hilbert.