How early on do we grasp this concept of nothing? Are there people who get old without that basic understanding?
Now, let's define nothing as the absence of everything. Yes, talking about any possible universe now.
This is not any longer obvious if anyone can even understand it. Suppose we can: how hard is it to do? Is it even possible to postulate a mathematical definition for it, thus, making it really hard but plausible?
In other words... While it will always be ambiguous, what is a good philosophical definition for nothing? If there really isn't any consensus (as it seems to me), then the answer automatically is something in the line: "No, it ain't easy at all", and then pointing why it isn't easy to understand (in lack of a better word).
Disclaimer: If you know portuguese, I'm deriving this question from a brazilian song. Please, don't mistake the question by "Is nothing easy to understand?". That is just obviously false. There are things that are easy to understand. And, specially, don't take this to ontology or methaphysics.