Don't get me wrong, I like hats. They're good for shading skin from sun or keeping ears toasty when it snows. They provide comedy at weddings, and can make an excellent disguise for unruly hair. However, all of these uses imply that you are outdoors and-slash-or in public. Maybe even at some sort of formal gathering.
Some times these circumstances are perfect for thinking (well, not the formal gatherings. Don't mull over gnarly maths problems at funerals, you'll accidentally shout out the answer during the eulogy). Long walks and sitting under trees, for example, provide perfect opportunity for be-hatted philosophising.
However, some thinking needs to be done indoors. Some thinking requires sofas, duvets, a selection of fine cheeses*, wine, maybe even a bit of paper and pen. These situations are incompatible with hat-wearing.
And so, I present to you, thinking socks. Wear with pyjamas, sweaters, and contemplation.
*okay, the cheese might just be me