Its the belief that the situation does not deserve certain expressions from you (joy, love, involvement, interest, fascination, wonder) that holds you back. If this belief stays persistent, it causes depression. When this belief is removed, the lost freedom is regained.
In fact reality itself is this infinite possibility space. Finding your true nature is finding out that ‘You are THAT’. You feel what you want to feel. If you think a mental/world model prevents you from doing this, then that is the belief illusion. This is because the mental model exists in a totally changeable thought space. Enlightenment is basically finding out that ‘You’ are the true essence of everything. No external object has any intrinsic essence. There is only ONE SPACE where everything appears and ‘You ARE that space’.