I have a full and satisfying life. My work and my family are very important to me.

It is extremely important to me to write for children.

All my adult life people have been helping me.

Work gives you meaning and purpose and life is empty without it.

Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity.

I can't say that my disability has helped my work, but it has allowed me to concentrate on research without having to lecture or sit on boring committees.