There are a few places where you highlight gotchas like this, but they don't stand out very much from the body text. When highlighting behaviour like this, I'd change the typography a bit to make it stand out.
You say "if we want to change the value of a variable, we must change its memory address". I think this is not right. We don't have to change a variable address to change its value. We just have to put the new value into the variable's address.