я не замечаю
I pay it no mind.
I take no notice of it.
I don't notice
Я думаю, здесь контекст имеет значение.
А где он не имеет значения?
I suspect what is meant here is that the person knows that something is afoot, but chooses to ignore or “not notice” it.
This is why I wrote that. Не замечать can mean both "not becoming aware" and "not acknowledging/disregarding intentionally". I thought there's a similar difference between "I don't notice" and "I ignore".
I’m glad you confirmed that because “I don’t notice” doesn’t really say anything.