The saying "Fear Is A Liar" means that fear often makes us believe things that aren't true. It's like when you're scared of the dark, and your mind starts imagining all sorts of scary things, but in reality, there might be nothing to fear. Fear can trick us into thinking that bad things will happen, even when there's no real evidence for it.
When we let fear control us, it can stop us from doing things we want to do. For example, it might make us think we can't succeed or that we'll fail if we try something new. But in reality, many times, our fears are just stories we tell ourselves. It's important to question those fearful thoughts and not let them hold us back.
So, remember, "Fear Is A Liar." Don't always trust the scary thoughts it puts in your head. Instead, face your fears with courage and you might find that they were lying to you all along, and you're capable of more than you thought.