Okay kiddo, so you know how sometimes mommy and daddy don't see eye to eye and they argue a lot? Well, that's kind of like irreconcilable differences. It means that two people (like mommy and daddy) just can't agree on things no matter how hard they try to fix their problems and get along.
For example, let's say mommy really likes to watch romantic movies and daddy really likes action movies. They both try to compromise by watching a little bit of each other's favorite movies, but they just can't seem to enjoy it and end up arguing instead. This shows that they have irreconcilable differences.
In grown-up relationships, irreconcilable differences can mean many things such as having different goals in life, not being able to communicate effectively, or even having different values and beliefs. When these differences become too big and can't be fixed, then it might be best for people to separate or get a divorce.
It's important to remember that irreconcilable differences doesn't mean that one person is right and the other is wrong. It just means that they see things differently and can't find a way to work it out.
Overall, irreconcilable differences is just a big grown-up way of saying that some people can't get along no matter how hard they try.