Mismatch loss is like trying to fit a square block into a round hole. When you have two things that are supposed to work together, like a radio antenna and a radio, they need to be a perfect match. If they don't fit perfectly, some of the energy gets lost, like when the signal is weak, or when you can't hear the other person on the phone clearly.
For example, if your antenna is not the right size or shape for your radio, it won't pick up as much of the radio waves as it should. This is because the radio waves are not able to travel through the antenna and radio properly. When energy or signal is lost, it's called a mismatch loss.
Think of it like trying to fit puzzle pieces together that don't fit: if they're close, some parts might go together okay, but there will be gaps in other parts, and the puzzle won't look right. Similarly, when two devices don't match up properly, there may be some electrical energy that gets through, but not as much as there could be.
So, to sum up, mismatch loss happens when two things are not a perfect match, like trying to fit a square block into a round hole. This causes some of the energy or signal to be lost, making it harder to hear, see, or use the device properly.