Robbert Dijkgraaf said this quote

“ I received comments on how extraordinary it was that I could keep up speaking for exactly 45 minutes. Indeed, in an age of soundbites lasting some seconds and of quick quotes in the news, all those minutes do seem like an eternity, easy to get lost in. Yet, wait a moment. Television is not the only place where speeches are given. Some hundred thousand teachers teach every day. They all speak 45 minutes, more times a day. They have been doing this for years. Every teacher knows exactly when the time will be over and that by then his speech will need to come to a natural end. It is this tension that determines the success of a lesson. It is a sign of the times that we forget these daily achievements in education. A million students daily attend several ‘live’ lectures and this in secondary education alone. These are high ratings! ”