I did the same transition … as a college freshman who wanted to be able to read my own lecture notes later that day. 
When I took the GRE I had to copy an integrity statement (basically promising I wouldn’t cheat). Having only printed since middle school or so, I started doing so, only for the proctor to stop me and tell me that I had to “write it. You know, cursive.” I explained that if I attempted that it would be thoroughly incomprehensible. That apparently wasn’t a problem. Printing it legibly was.
Weak OP. Plenty of maps returned by an image search for “east coast map” have all or part of TN. Regional names are fuzzy and their meaning is contextual. Classifiers are often imperfect. Welcome to how language works. PA and VT don’t touch the Atlantic but can still be on the east coast. Knoxville is farther east than Atlanta, and Pensacola is farther west than most of TN. Planning a road trip of east coast national parks? You might visit Smokey Mountains. Maybe even Mammoth Cave.
Hmmm, I grew up in the northeast (I’m now living in California), lemme see…
The OP is —
Yeah @Ruken , I agree with you. Even though Tennessee touches the Mississippi River, only North Carolina is between Tennessee and the Atlantic Ocean.
Yeah - four hundred miles of North Kakkalakky. That’s like saying Nevada and Idaho are on the West Coast.
They’re in the West. They’re not West Coast.
Exactly - Tennessee is in the East, but not on the East Coast.
Reno and Vegas are heavily connected to California economically and culturally, so they could be considered West Coast (altho the rest of Nevada less-so). There is no place in Idaho I would consider West Coast, but Spokane, in eastern Washington is more closely aligned with the inter-mountain region (Idaho, Montana, and BC) than the west coast of Washington.
I can see In-n-Out thinking Tennessee being the headquarters for their “East Coast” operations, if you think about just dividing the country into two sections for management purposes. It’s not like the city needs to be on the ocean - otherwise Baldwin Park (their West Coast HQ) isn’t coastal enuf (it’s about 30 miles from the beach)! How pedantic do we want to be?
I worked in Carisle, Pennsylvania, for a while. It seemed like every trucking company had a big facility there. Someone told me that Carlisle was within a ten-hour drive of more pf the U.S. population than any place else, and ten hours was the limit for how long a truck driver could work without time off. So I wouldn’t say it was on the east coast, but business needs connected it very strongly to the east coast and the population centers thereon.
Very good question. It’s like a variation of Zeno’s “Dichotomy Paradox”:
Suppose Atalanta wishes to walk to the end of a path. Before she can get there, she must get halfway there. Before she can get halfway there, she must get a quarter of the way there. Before traveling a quarter, she must travel one-eighth; before an eighth, one-sixteenth; and so on.
It suggests that there are an infinite number of fractions of distance to cross, and no matter how small those distances are, you can never cross an infinite number of distances, therefore motion is impossible. Similarly, every location you pick has some distance between it and the shoreline, therefore nothing is objectively “on the coast”, and instead you have to pick some arbitrary definition of what counts as being a coastal location.
It seems to me that whether or not a state is coastal is pretty objective… If that state has a coastline as a border, it is a coastal state. Even if there are parts of the state farther from the coast than a neighboring state that doesn’t actually touch the coast. That’s an easy, objective determination to make. That arbitrary definition that I mentioned earlier was already decided by whoever defined the borders of a state. Therefore, Tennessee is not on the east coast, even though west Texas (for example) is farther from the Gulf coast than eastern Tennessee is from the Atlantic coast.
Even Hawaii?
Of course! It has a Pacific coastline, a lot of it (by ratio). If you were to ask, “Which US states are on the Pacific Ocean”, that absolutely would be one of the answers. (With Alaska, Washington, Oregon, and California.)
It is not part of the contiguous US Pacific coastline, but that is adding some qualifiers.
Sociologically, which teenager is or is not a “Coastie” can seem important.
So a Hawaiian would be a Super-Coastie!
Are those people in Venice Beach on their inline skates “Roller Coasties”?
Go to your room.
(Oh, YES! All my stuff is there!)
My mom still laughs at how sending my daughter to her room was excruciating (“There’s no one to TALK to up there!”), but I cherished the quiet.
And I still do: six decades later, I just spent three hours reading and drawing (with headphones on, listening to a book).
I didn’t have to be sent to my room, I had to be dragged out, kicking and screaming. 
After decades of seeing comments like that, I’ve often wondered… are there any extroverts on this board?
(Anybody want to start a poll? That sounds too outgoing for me…)
I’m an extrovert according to personally tests. And I have a very customer service-focused career so I’d pretty much have to be.
Just the same, I enjoy and sometimes need time to myself now and then.