If I'm a number in this hypothetical: irrational numbers get to wreak more havoc. I think I'd have some fun there.
If I'm a person: I'd probably enjoy being someone's imaginary friend, or someone's imaginary strawman. And if I'm just some random fleeting thought, I'll be gone before I can complain about it.
Would you rather know about everything but that which you currently need, or forget everything except what you need right now?