How you celebrate your wife's birthday or your anniversary is an art, not a science.  The scientific approach puts a lot of stock in the material, the expensive.  Suppose one man buys his wife a Mercedes for her birthday.

The other man takes his wife out to the park and they go for a nice walk and share feelings of love and closeness as he tells her how much she means to him.  On the way back to the car, he finds a small, flat rock, picks it up, and brings it home.

Then he writes a little poem or some other notation on it and presents it to her as a memento of the walk they took that day.  Whose wife will appreciate her gift the most?

The natural male inclination is to think that the expensive gift would be far more meaningful to a wife.  After all, if you bought another man a Mercedes, he'd go around telling all his friends, "Wow!  What a great guy Joe is.  I can't believe it.  He gave me this wonderful car!"

But when you buy a woman a Mercedes, she is much more likely to say to her girlfriends, "Look, he got me a Mercedes.  I wonder if he is trying to buy me off or something."

Let's get back to that little rock.  When she's 93 and you've been dead for a decade, what is she going to keep on her mantel?  A picture of the Mercedes?  Absolutely not!  She's going to keep that rock, because it symbolizes a time when her husband gave her special attention, devotion, and esteem.