Even if one is physically challenged, he need not blame his fate and become depressed. He can motivate himself by reading the great achievements of famous people. 

The most outstanding example is Helen Keller - She lost both her sight an d hearing, when she was just 2 years old. But she did not lose her inspiration. She graduated from Radcliffe college and eventually completed her doctorate. She authored many books and taught in many Universities. 

Thomas Alva Edison was totally deaf. He was considered stupid and the schools were not willing to admit him. But he did not lose hope. He went to become a prolific inventor, patenting more than one thousand inventions. 

Franklin Roosevelt, contested and won the US Presidential elections, despite the fact that both his legs were paralysed. He won not once, but four times and created history. 

Van Beethoven, created masterpieces in music, despite suffering from total deafness and poverty.