Possible Clues:

• There's five hundred and ten in it, stupid!
• Dimwit using computers to grasp 500 + 10?
• Dostoevsky's Myshkin, e.g.
• Sap
• Dostoyevsky masterpiece (with ''The'')
• I would be foolish to have a tent like this, perhaps
• Prince Lev Nikolayevich Myshkin is the central character in The ____
• I do get muddled and stupid in it
• Fool I spot, one to be taken in
• One did almost nothing with time, being a fool