When I was at the Children’s Museum with my grandchildren a few months ago, I noticed a woman, a nicely-dressed, normal-looking woman, who had on her arm a tattoo of a large housefly. I hope I didn’t stare but for several minutes I contemplated the question: Why would anyone want to sport a tattoo of a housefly?

And recently I chit-chatted with a young woman who was helping me download photos from my phone in order to make prints. She mentioned to me that she and her fiancé had recently had a party to celebrate their engagement. I asked her when the wedding would take place and she told me August 24.

“Wow, that’s coming up very soon,” I said. The girl smiled and explained, “Oh, we are definitely getting married on August 24, but we haven’t decided yet on the year.” Why would anyone choose the month and day for a wedding but not the year?

Most of us have read about people who amass collections of unusual things, and again we ask why.

Why would anyone collect:

Umbrella cover sleeves? One woman has over 700.

Banana stickers? Someone has more than 7000.

Airline barf bags? One man has over 6,000 (hopefully empty) such bags from over 200 countries.

Admittedly, most of us occasionally save too many or too much of a thing. A friend told me several years ago that her mother always saved the TV Listing Guide that came in her newspaper. To designate which guide was the current one, she wrote on the front of the guide with a wide-tipped, black marker the words: THIS ONE. But she never threw an old guide away. Therefore, at any given time the woman had in her living room numerous TV Listing Guides all labeled: THIS ONE.

I too have collections of things I would never consciously choose to collect: plastic grocery bags, paper clips, twist ties, and shoe boxes. Those things are all useful given the right circumstance and the right time, so I hang on to a few to too many of them.

I even indulge in a few ridiculous practices. Whenever I read a book that I did not find particularly entertaining, I write inside the front cover of the book the initials N.E.G., which stand for “Not Especially Good.”

I do the same thing with recipes that turn out to be flops. But do I get rid of the books and recipes I have designated to be not especially good? Of course not! I put them right back onto my bookshelf or into a kitchen drawer.

It is as if I think that some night when I want to try a new recipe for a broccoli casserole or want to read a book for relaxation, I will choose one I have labeled N.E.G.

Why do I do that?

Maybe I am as weird as the woman with the housefly tattoo and the man with 6000 barf bags. But I don’t think so.

The difference between being odd and being weird is this: When I or people I love demonstrate unusual characteristics, we are simply odd. When other people do strange things, they are weird.