security – doubt about the generation of private keys

I've read that the private key pk must be a number between 1 and not, or not is almost 10 ^ 77.
Since pkThe function of is practically used as scalar to multiply the generating point gwhy should it be strictly inferior to not?

I thought it was because the calculation behind Secp256k:
inside an ordernot group, if I multiply x a number A (with x> not), it's equivalent to multiplying the same number A y times, with y = x% n. So, there will be extremely lower than x, which makes A easier to discover.
Is this argument correct?