The concepts exist in the same moment, else they would have no meaning.
Within the dream of separation where these two concepts are divided by definition they don't exist at the same time, of course.
But in reality...there is nothing that is true or false, except within the conception, aka the story, aka a dream.
In reality, nothing ever happened, happens, or is happening in a dream.
There is no 'you' to mix or negate with opposites, except as an idea.
"I" is the empty awareness that I AM = (empty and full at the SAME TIME)
Objectifying what I am as a subjective entity is making a self of what I am. As soon as this concept becomes a reflex action (usually very early in life) I am in bondage to that concept.
Losing one's 'self' in what is Here is finding that 'Here" is what one is. = EMPTY AND FULL AT THE SAME TIME.
Is a glass of beer filled half way... half full or half empty? ...it's both at the same time, depending what thought wants to impose on the observation.