As previously mentioned, we can't help but turn into our parents.
But we can control the things that we say. There are things that old people say that automatically make them sound old.
If you ever start your sentence with When I was your age, then young people will stop listening to you instantly.
When you say I used to walk 8 miles to school, uphill both ways, in the snow, no one really believes you. You are then labelled old, and for good measure you are now also crazy.
At my parents house they have a table older than me. It is sturdier than we give it credit for being. Yet whenever a child comes near it everyone over 25 says Don't lean on the ends of the table, they're only held on by pins. Call me crazy, but I don't think after three generations of abuse those table ends are coming off. Or maybe they're still there because of the caution taken by all the adults?
If a new song comes on the radio, and your response is not tapping your feet along with the beat and singing along, but saying All these songs sound the same these days. Kids these days have terrible taste in music. Just stop listening to pop music then. Listen to your fuddy-duddy old songs that the adults of your childhood looked down on.
When you go shopping, please refer to sandals as flip-flops or something of that nature. If you walk into the store asking Do you have any thongs for kids?, the sales clerk will look at you like you're speaking another language.
Nowadays, we only call womens underwear thongs, so if you say that, that's what people will think you're talking about. And they will picture little thong underwear for children. Maybe kids these days have too many visible panty lines and we need to do something about this immediately, but thongs for kids isn't the answer.
Anytime you say I remember when...insert stereotypical thing like kids didn't have cell phones, people had morals, people didn't watch so much tv, computers didn't exist (you get the picture). People are always evolving and our culture is always changing. Kids didn't have cell phones when I was in high school, and that was ten years ago. Now we're all texting and surfing the internet on our phones, and not listening to old people.
Most of the time if you talk about your medical problems, your grandchildren won't listen that closely. These new orthopedic shoes I got were so expensive. Stupid Medicare didn't pay for them. For me personally, I don't really want to hear a ton of detail about anyone's medical problems, so hearing about your cheese allergy isn't that compelling to me.
Last but not least, complaining about the price of things makes you seem old and cheap. Everything's just getting so expensive, I remember when a gallon of milk was 5 cents. Prices get higher. Thats just how it is. And milk will never again be 5 cents a gallon. Never.