“Madness in great ones must not unwatch'd go.”—Hamlet 

Nothing wrong with sanity.  Let's face it, our day-to-day lives run a heckuva lot smoother knowing that most of the folks we brush elbows with have the lion's share of their nuts and bolts in the right place.  And yet, I'd be hard-pressed to think of any of the personae who have moved me over the years who didn't appear to be working out some issues.  I'd go as far to say that there is an inverse relationship between the amount of inspiration I've drawn from the individual and their grasp on reality.  I'd probably go even further, but you'd probably send out the padded van.