I've been thinking about this a lot over the past year or so.
We're evolving creatures. All we know is limited by our senses and instruments. We don't have perfect senses, not by a long shot. We can't hear every pitch, we can't see every spectrum of light, we can't smell all there is to smell. We're limited.
All of this limited information goes to our limited brains, which again, are only as developed as our current models. What we sense is a watered down version of reality. But not reality. What we are is limited too. Although we seem to think we have the monopoly on life most of the time, a plant or an ant probably 'thinks' the same thing. Their existence is enough for them. Ours is enough for us.
It is for me most of the time, but sometimes I envy future creatures who will experience more of reality than I ever will. I'm only getting a glimpse into the possibilities.