What does burning your bridges mean?

Answer 1

Burning your bridges means leaving jobs and other relationships in such a way that it would be difficult or impossible to ever go back again.

During battles, soldiers would burn literal bridges to keep their enemies from crossing, thus giving them a strategic advantage. However, they would have to make sure they burned the right bridges and that they didn't need them later for supplies or more troops. You would not want to trap yourself in your enemy's territory without supplies nor the ability to flee. Similar can apply to personal relationships in that you don't want to cut all ties with a person whom you may need later.

If someone is very critical of you and won't stay out of your life, then "burning bridges" with them might be a way to get them to leave you alone. However, completely alienating other people is a poor strategy for dealing with life in general, and it is often easier to destroy relationships than to rebuild them. You might alienate the very people you may eventually need to support you or help you in your life, and they won't be there for you.