I am approaching what may be thought of as a significant birthday next month. I’m not sure what makes it significant except the number attached to it.

If we don’t know how old we are, most people, including the elderly, will think they are younger, even if they have arthritic knees. If they take a morning cocktail of pills, they will still think they are much younger than the calendar dictates.

So, here is my guide to knowing, empirically, how old you are. You are old if …

—You remember when all restaurants served half a grapefruit with half a maraschino cherry placed in the middle.

—You remember when restaurants had relish carts with things like watermelon pickles and herring in sour cream.

—You remember a whole class of singers called crooners and you still get a bit weepy when you hear their songs.

—You remember when men’s trousers had buttons instead of zippers.

—You remember when women wore girdles with attachments for stockings.

—You remember when cars had little arms for turn signals, called trafficators, that wouldn’t go up at speed.

—You remember when airline tickets were as good as currency and could easily be exchanged or sold back.

—You remember when flying was a pleasure, even in coach, and you felt pampered, not herded.

—You remember when hotel rooms were rented for fixed prices, and those were posted.

—You remember when sneakers were all white and for tennis.

—You remember when men wore hats and baseball caps were worn just to play baseball.

—You remember when women wore hats and gloves to church.

—You remember when men wore suits to church or just put them on so their neighbors thought they had been at worship.

—You remember when birth control, if available, was with condoms, known as rubbers, and kept under the counter at drugstores.

—You remember when drugstores also had lunch counters.

—You remember soda fountains.

—You remember when Coca-Cola came only in a 6-ounce bottle and tasted better because it had cane sugar and the bottle seemed to concentrate the carbonation. Also, it cost a dime.

—You remember five-and-dime stores where some things really cost only a dime.

—You remember when shopping centers were novel and a place to visit.

—You remember when going to the movies was an occasion. An usher showed you to your seat with a flashlight. And a popcorn, ice cream and candy vendor walked up and down the theater aisles.

—You remember when cigarettes were offered at dinner and ashtrays were part of the table setting.

—You remember when Americans didn’t drink wine, and only glasses for hard liquor were on formal dinner tables.

—You remember when ethnic food was Hunan Chinese, often called Polynesian, and French food wasn’t regarded as ethnic, simply hard to pronounce.

—You remember a time when comfort wasn’t important to you, when you didn’t ask, “Are the beds comfortable?” And when on a road trip, you didn’t expect to sit in the front seat because “it is more comfortable.”

Recently, a woman — who had been to a few rodeos herself — looked at me and said, “You’ve got age on you.” I was about to remonstrate, but I realized that while her manners were wanting, her eyesight wasn’t.

Therefore, I shall be bowing to the calendar and, after next month, I will gladly let people hold doors for me, help me with grocery bags, and offer a chair when there is a lot of standing about going on.

My wife is taking me to Montreal for the big day, but I plan to treat it as nothing to do with moi. Other people get old. They always have — as I remember.