Ask HN: Situations when people changed their behaviors / habits?

Some examples:

I think that grocery store analysts found that mum's are likely to change their purchasing behavior before/after the birth of their child. The new habits might stick for a long time.

Sometimes (not always) I change some behavior when I read a book.

I know people who stopped eating meat almost entirely after they watched a movie about the meat industry. The reason was that they felt disgust and were not able to eat it any more.