I don't think I have a conscience...?

Not to get psychological, but did anything happen when you were younger? Such as a lot of pain, physical, emotional, or mental that could have hurt you in some way? Too much of that actually dulls your senses, to where you just take it in, it almost 'bounces' off you. This is actually a very common thing, and theory. Maybe a little more happiness, or joy in your life would help strengthen your conscience.