Possible Clues:

• The thickest hooligan loses the head and takes drugs in race
• Least intelligent
• Most stupid old boy facing ordeal, getting you and me involved
• Least intelligent pupil previously useless in exam
• Broken toes, small but extremely thick
• Stub toes carelessly: most stupid
• Stubs toe painfully, being most stupid
• Nothing but devastation for skinhead in place ¿ that's the most stupid thing
• Zero on bungled subtest? That's extremely stupid