What do "stay the same" and "in a matter of moments" mean in this following context?

Question

I'm reading a book which is about how to maintain a good relationship with women. The book has a paragraph:

Do not change yourself for women. If you change your behavior drastically for them, they lose the attraction as it was another behavior they were attracted to initially. In the same way, if you met a woman because you were attracted enough to approach her, her best strategy to keep you is also to stay the same. The biggest difference is that she has little control over some parts of her body, such as the pace at which she ages, but you have lots of control over your behavior and can really ruin things in a matter of moments

What do "stay the same" and "in a matter of moments" mean in this following context? And why did the writer write "In the same way, if you met a woman because you were attracted enough to approach her, her best strategy to keep you is also to stay the same"? Thank!

Answer 1

"To stay the same" means "to not change". Stay is used here to mean "to continue to be in a particular state."

"A matter of [plural noun]" is an idiom used to emphasize that an amount is small. In my experience, it's usually used with nouns that measure time, like "seconds," "minutes," "moments," and so on. The phrase implies that the event takes place quickly.

In a matter of seconds, the building had fallen.

In a matter of days, the army will take back the city.

In your source, the author is saying that if you do the wrong thing, you can "ruin things" very quickly.

Contrast this phrase with the similar-sounding idiom "a matter of time," which refers to events that are inevitable, but not necessarily those that would happen quickly.