FORT WORTH, Texas -- Across the country and all over social media, everyone was celebrating National Taco Day today. But one Fort Worth man planned to eat tacos no matter what.

David Millar is on a mission to try every taco in town at least once, no matter whether it's at a traditional taqueria or an ice cream shop. "It's easy to find tacos. It's just hard to try and find all of them," Millar said.

He takes meticulous notes on what he tries in a notebook, and he then blogs about his experiences at AlltheTacos.com. A map with pins dropped across town shows the places he's sampled and the pile of other recommendations he's yet to try. "I'm at about 337 tacos right now," Millar said.

He grew up in Michigan, where he says he only knew the taste of the traditional fast-food or Tex-Mex taco, a crispy shell filled with ground beef. But when he moved to Texas five years ago, he said his taste buds were introduced to a whole new world.

The success of National Taco Day is just one sign of the taco's slow takeover of American tastes. According to the group behind the day, Americans ate some 4.5 billion tacos last year.

Fort Worth has seen its own taco boom, with new taquerias opening seemingly every week in areas like West 7th. A TCU professor even attempted to map all the taco joints in town earlier this year, finding 125 different restaurants. But Millar said the menu is constantly changing, with new places serving tacos all the time.

When pressed, he says his favorites are the pastor tacos at Salsa Limon and Los Taco H's. "I think tacos are a really good vehicle for flavors," said Millar. "I really see tacos as a vehicle that are approachable by anyone whether it's one of your most savvy chefs or just amateur cooks that want to try things at home."