Once more unto the breach, dear friends

While grocery shopping a few days ago I got a 1919 penny in my change. The late night talk show host Jimmy Kimmel has a bit in which his cousin asks people, on the street to name the presidents on coins and currency. If they get it right, they can keep the money. The ones he asks are usually under thirty and they do shockingly bad. That's something that's likely to be more true (and less shocking) as cash increasingly become obsolete. If someone came to America from the year 1919 with cash, he or she could spend it freely. If you went to sleep now and woke up in 2119 and had only cash, it's unlikely you'd be able to buy anything with it. There are already stores that don't accept cash, though this is controversial and rightly so: Look at any bill and it says it's legal tender for all debts, public and private. 
I like old coins. This penny is now a century old and you can see from its worn condition that it's spent most of that century out there serving its purpose. John F. Kennedy may have used it to buy a gumball when he was a child. It may have jingled in the pockets of Groucho Marx and Ernest Hemingway. Rosa Parks might have used it to pay for a bus ride. Maybe it was spent time overseas. Maybe it was in your grandmother's piggy bank when she was ten years old.
Coins have stories that only they know.

Some United States coins, including a 1919 penny.

I worked as a cashier for years and I have several dollars worth of wheat pennies, which were made from 1909 to 1958 (1909 and 1959 were the centennial and bicentennial of Abraham Lincoln's birth). They're not worth much unless they're in perfect condition. Even then, it helps if they were made in limited quantities. This one, for example, is one of 392 million. If I'd found a 1909-S (meaning it was made in San Francisco), that would mean I'd have a penny that was just one of 1.8 million. If this were in average condition, it might be worth 35 cents; if in certified mint state it would be worth as much as 60 dollars. All wheat pennies are worth more than their face value. (I used cointrackers.com for much of the above, my Whitman coin folder for some of it.)
What will I do with this penny? I have so many wheat pennies, including this one, that instead of having it sit in a stack or lie in a bag, I might shine it up (yes, I know that destroys what little value it may have) and put it back into circulation. It may be snatched up by one of those nuts who hoards copper (i.e., pre-1982) pennies thinking they're going to make a killing selling them for more than they're worth—a fool's quest, as the copper in pennies can't be purified enough for commercial use and it's still illegal to melt down U.S. currency. Or it may stay in use for even more years beyond the average twenty-five-year lifespan of a coin. It may be out there until the end of cash.
Bonus Fun! Ask someone who takes pride in being observant which way the portrait of Lincoln faces. Answer: to the right, which is the opposite of all other coins. Another question you can ask someone about pennies with the memorial on the back is how many times does Lincoln appear on the penny? The answer is two, which you can see even in the photo here.