This is Hans Krebs, who in 1937 published a paper showing the sequence of chemical reactions, by which energy is released in individual cells. It is called the Krebs cycle, which some of you may remember from your chemistry course in your high school. Krebs is a wonderful example to me of how a scientist who is determined can overcome all kinds of human obstacles. Krebs’ father constantly discouraged him and told him that he had just mediocre intelligence whenever to anything important in his life, as a teenager. What Krebs remembers in his memoir, his father said to him "you can't make a silk purse out of a sow's ear". And later on, when Krebs studied with the great biochemist Otto Warburg, Warburg also told him the same thing. Not the same quote but that he had only mediocre ability and would never be a great scientist. And we all hear about how important it is for parents to encourage their children, but sometimes the children will go on to do great things no matter what we say to them.