Yep yep. I have noticed the famous female ancestor slowed aging trick. Have also found the male ancestor suddenly being a bit older trick too. Funny how they are just exactly old enough to enlist in the armed forces when they want to go.
On the other hand, sometimes you get surprised. One of my relatives was from Slovakia/Hungary and he lived in Chicago and was married to a woman named Joanna from Germany. He had a child from a previous marriage and they had a child together. I found them in several censuses and on other docs like passport applications. But I really didn't get why her age changed so much, like by 10 years or more.
Then I found her death certificate. And a marriage certificate for her a few months later. Whaaaaaaa???? Turns out my relative was married to two different women named Joanna from Germany! The first one died shortly after giving birth so he married again pretty quickly and the new Joanna raised the child as if she were her own (meaning she treated her like her own, not that she pretended she was her biological child).
This is part of why I record every fact and every source. Even things that seem out of place or that are duplicates.