You enter into the room to realize it is a bathroom!

One of the things that happens to us as we grow older is that our past life begins to influence our future experience. Everything we do conditions us, so we wind up with layer upon layer of preconceived notions that distort our perceptions.  Jesus understood that when he gave this warning.To enter the Kingdom of Heaven, we don't have to turn off our intellect or ignore our hard earned discernment, far from it. But we must put aside our preconceived ideas and take the filters off our minds so we can see things as they really are, and not as a reflection of some past event.  Knowing the Kingdom of Heaven is an entirely new experience, unlike anything we have done before, and to know it, and enter it, we must see it as it is - as a child would see it. Living in the Kingdom is as simple as living your life in harmony with the nature of God. Jesus told us what that nature is in the two great commandments.  Love and forgiveness; that is the nature of God. And if you want to live in the Kingdom, right now, do those things.
Just do it!