If you want to name the most incompetent president, Franklin Pierce has to take the prize. He's probably the "most forgettable" one whose name Little Hawk couldn't remember and that fact is probably the reason his gross incompetence is unremembered.

Essentially, Pierce was someone who enjoyed nothing more than a convivial evening (read: drink, and plenty of it) with his friends. Unfortunately, in his conviviality he found it impossible to say "no" to anyone and thus ended up making multitudes of diametrically opposed promises which he no chance of being able to keep. Probably the biggest reason his administration was so ineffective and easily forgotten.