i have to write a story for english and the prompt is "behind bars" but i would like something different from jail etc ty

Think of something that's already been holding you back. Like if something bad has happened to you example if you have had depression or anxiety this locks you behind bars from the real word and limits your abilities. Or if you've ever been shy to do something this also locks you "behind bars". I'm also assuming your in school so that could also be a metaphor for being "behind bars"