I'm simple for a few people. But hard for them to hear. I live inside of secrets. I bring people's worst fears. What am I?

Answer: The truth.

More What am I ? with answers

More What am I ?

I'm smaller than a mouse, but I can fill a whole house. What am I?
I'm so fast you can't see me, though everyone else can see straight through me. I don't stop until the day you die. What am I?
I’m so simple I only point, Yet I guide people all over the world. What am I?
I'm tall when I'm young and I'm short when I'm old. What am I?
I'm the manly mark that milk makes. What am I?
I'm under your face, I'm outside your mind; A biological case, Pressure brings pain sometimes. What am I?
I'm where yesterday follows today and tomorrow is in the middle. What am I?
I'm white, and used for cutting and grinding. When I'm damaged, humans usually remove me or fill me. For most animals I am a useful tool. What am I?
I’m white, perfect for cutting and grinding. For most animals I am a useful tool. What am I?
I'm with you some days, but not on the others. I fall short on you always but mostly in summer. What am I?
I’ve been argued on my colour. Without me you’ll die. So many attempts on your life use me, so make sure you have many of my “White” friends. What am I?
I've got 4 eyes, 3 legs, 1 tail, and 12 toes. What am I?