Theodore Roosevelt had a sickly childhood characterized by asthma attacks but developed a strong desire to live fully. He overcame his physical weaknesses by lifting weights and learning to box. He went on to have a hugely successful career in politics and writing. Alfred Adler was interested in what allowed some children to thrive despite illnesses while others did not. He developed his theory of Individual Psychology to explain this. Adler believed people are motivated by a drive for perfection and the realization of their ideal self, which is influenced by their social environment and desire for social connection with others.