In a May 2015 article Deutsche Telekom CEO Timotheus Höttges was asked what his biggest management mistake had been thusfar in his career.
Höttges responded that in his days as the head of T-Mobile Germany back at the beginning of the 2000s, he was very motivated and came up with at least one new idea every day of the week.
He admitted to demanding too much of the managers and employees. In doing so he overwhelmed the entire company. Höttges said that he had learned over the years. Today he focuses only on what has been agreed upon. Even if he has ten other good ideas.