Inside, Within
Your head has a person inside it!
And, you have no idea how to get them out. They're inside for good, and it's freaking you out. As in, there's a little person in there, running around, controlling your brain. People think you're crazy, but you know better... He's inside there, doing evil things.
ない
うち
None
You know this kanji means inside, so you can keep thinking about the person that’s inside you, running around. You finally discover him, and try to take him out, but before you can, he pulls out a knife (ない) and threatens to cut you if you do anything irrational.
Imagine him holding the knife out, threatening to stab your brain. You’re in a conundrum here. If you don’t take him out, you’re in trouble, but if you do try to take him out, he might stab you in the brain with his knife. Try to think a way around this situation, focusing mainly on his knife.