Hello Olympia,
Diaries are just one way of evidencing the problems you have with Daily Living and Mobility. I find they are particularly useful when the problems are less obvious, eg mental and developmental health, they are also a way of being able to submit evidence if more formal evidence from medics is not available.
But to answer your question, I know many people who have won the correct, including enhanced, awards without completing a diary.
Catherine
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
