Okay, so you know that when you are playing and having fun, it can be hard to stop and do something else like eat dinner or go to bed. That's because you are experiencing inertia, which means you want to keep doing what you are doing because it feels good and it's familiar.
Now, imagine if you were feeling sad or angry about something, and you couldn't stop thinking about it even though you wanted to move on and feel better. That's what we call psychological inertia, and it's when our thoughts get stuck and keep us feeling down or frustrated.
Sometimes, we might keep doing things that don't make us happy because we are used to them or because we don't want to change even though we know it would be better for us. That's also a kind of psychological inertia, and it can make it hard to grow and learn new things.
So, psychological inertia is when our thoughts and behaviors get stuck, and we have a hard time changing them even when they are not helpful to us. It's kind of like being glued to the spot and needing some help to get moving in a new direction.