A hat is made to protect your head.
You never know when some pterodactyl will swoop down and snatch you up by the head and carry you off to Jurassic Park. A hat of the proper design will disguise you as something inedible. Therefore, it is suggested not to buy the Finding Nemo fish hat in case there are hungry albatrosses around.
A good first hat would be something in a classic style. The pointed hat is still very popular. You can wear a paper one that you kept from your school days, or buy a cloth one reminiscent of Harry Potter or your favorite garden gnome. And it will keep those pesky pterodactyls from roosting on you head while looking for other prey.
A good quality hat can even deflect a bullet or even an artillery shell. It has to held at exactly the right angle, though. This also provides the perfect opportunity to make French fries but putting a potato on the hat. There's nothing like hot French fries, is there?