Perception is the psychic's main tool. Perception isn't just how we see things, but also how we make them be. Several examples: A key is just an oddly shaped piece of metal unless you know it can be used to open a lock. Fruit becomes food after you realize it's edible. Color isn't color until the brain makes it be.
You don't really know a thing until you know all its relations to everything else - and many of these relations can be decided by you, effectively creating the reality of that thing. Psychic perception isn't just passive - psychic perception is also active.
Many of the deep layers of reality are invisible to us, hidden in plain sight. We don't see them because we don't look for them, and what we do see we dismiss because these perceptions don't fit the reality we wish to see. A psychic does his or her best to maintain an open attitude and work on perceiving directly instead of just operating with shallow (and often incorrect) assumptions.
A psychic prison is an ugly thing. The good news is that you have the key to get out - since you were the one to imprison yourself in the first place. The are two common types of psychic prisons: emotional and mental.
If you cannot discard your own thoughts easily and if you attribute much importance to them, your own patterns of thinking can become a mental psychic prison. If your mind and perception are not open, you can see things only one way and that can be very frustrating.
If you lack the self-discipline to control your emotions, your emotions will control you and this is a form of emotional prison. It feels like your existence is limited, and many people try to escape it by increasing physical action to feel something different - generally without success. Without developing self-discipline and taking control of yourself, this prison is almost impossible to escape.
These psychic prisons can range from small obstacles that you seemingly cannot wrap your head or heart around, to full-blown existential problems that manifest as physical, bodily illness and severely hinder day-to-day life.