Straw that Broke the Camel’s Back

This is a fantastic phrase in Spoken English. 
 Every native speaker knows this phrase and uses it.
                                                                                                              Imagine a camel, or any animal, carrying very heavy weight
on their back as they walk through a dry hot day. This animal is super tired and hurt.  If any more weight is added, the animal’s back will break.  It is the maximum the animal can handle.                                                                                                Well, we use this phrase with people.  Imagine you are getting angrier and angrier at your girlfriend or boyfriend, or you are getting more and more unhappy with your job.  If one more little thing goes wrong, you will either break up or quit.

You won’t break up or quit just because of that one little new problem alone, but you will break up or quit because you were already near your limit and you couldn’t handle anything else bad happening.  You could say, “it’s the straw that broke the camel’s back“.  A straw is very very light.  But thousands of straws together could be heavy.  One more little straw might “break” you if you are near your limit.

Your boyfriend might ask you, “why did you break up with me just because I forgot to call you on the phone tonight?  That’s crazy!” and the girlfriend might say.  ”It’s not only that.  I’ve been angry with you for a long time.  I guess it was just the straw that broke the camel’s back“.