"He is not a man that is easy to draw out, though he can be communicative enough when the fancy seizes him." Stamford, describing Holmes to Watson in A Study in Scarlet.
"If I am to lodge with anyone, I should prefer a man of studious and quiet habits." Dr. Watson
"I get in the dumps at times, and don't open my mouth for days on end. You must not think I am sulky when I do that. Just let me alone, and I'll soon be right." Sherlock Holmes