I understand that the meaning is loosely something along the lines of "Asking me so suddenly... I don't know!".
But I want to understand the function of も here.
I thought for a time that it is concession e.g.
But in this case it doesn't make sense. Something was asked a question he doesn't know the answer to or doesn't understand, the more time you give him, the probability that he won't know or understand is lowered, thus the highest probability of him not knowing is you ask him いきなり.
But if we understand the も to be concession then it translates as: "Even if you ask me out of the blue, I do not know/understand!".
But asking out of the blue is harder than giving him 4 hours to think about it.
So I think that "Even if you gave me 4 hours to think about it, I wouldn't have known!" makes more sense for a concession than out of the blue.
So given that line of thought, which function does も serve here? Is it も of emphasizing? Like 三時間も待ってたよ！
Or is it's use as an emphasizer is limited to emphasizing quantities?
Any help is greatly appreciated! Thanks!