Possible Clues:

• Intellectual from Clare gets real about brother
• Intellectually stimulating
• British Rail breakfast perhaps about to make you brainy
• Brainy brother into grass
• Apply wax to support student that's brainy
• Highly intellectual
• In class, as it turns out, be rare intellectual
• Little brother in a grainy setting that's brainy
• Corn flakes possibly protect British intellectual
• Cold beer handed out — right for nearly everyone brainy