Knit hats...fashion or function?

We're beginning to feel some crisp fall air here in Indianapolis.  While I know in just a matter of weeks I'll be wishing for spring, fall is always anxiously awaited.  The break from the humid 90 degree weather is always appreciated and of course I look forward to fall clothes and true "football weather". 

Speaking of football, the roof was open in Lucas Oil Stadium Sunday (Colts 4-0!!!).  Although it was only in the 60s, the sun was blazing and it was hot!  As I was sitting there sweating and the denim of my jeans was burning my legs, I couldn't help but notice the people wearing knits.  I even saw a guy donning a Flap like the hat pictured below: 

So my question to you loyal Lids-blog readers is, do you rock a knit hat to keep your dome warm or as a fashion statement?