Well, because he looked around himself and he saw all these fabulous physicists that created quantum mechanics and modern physics, and they were all in their 20s and early 30s when they did so.
حسنًا، لأنه نظر من حوله ورأى كل هؤلاء الفيزيائيين الرائعين الذين صنعوا ميكانيكا الكم  والفيزياء الحديثة وأوائل الثلاثينات عندما فعلوا ذلك