(1) All life on Earth is based on DNA. There is no alternative, no second choice, no runner up.
(2) While there are millions of species on Earth that have long been stable and successful and still are, humans have by some astronomically wide margin the most powerful capabilities with, again, no alternative, no second choice, no runner up.
(3) For all we have done with working with information, computing, human physiology and psychology, we still have hardly a weak little hollow hint of a tiny clue how to program a computer to be as smart as a human, dog, kitty cat, dolphin, or ... many more.
(4) On the one hand, humans, both individually and collectively, commonly make serious, disastrous mistakes for even just silly reasons. On the other hand, humans have made shockingly good progress even at understanding the universe. How could the same species have both such big disasters and bit successes?
(5) As we try to understand the universe in greater detail, we get in effect 'throttled': We can't go faster than the speed of light; we can't look in detail at a scale much smaller than an atom; we can't have energy enough to explore all the possible particles. In each case, we are throttled, and essentially blocked, not by hard barriers but just by increasing costs.
(6) As mentioned by others, the Einstein, Podolsky, Rosen (EPR) spooky action at a distance paradox.
(7) There is a naughty boy in his room with his relatively large computer. He types in candidate laws of physics and then clicks on the button Big Bang. Mostly all he gets is a fast poof but occasionally he gets something interesting. How do we tell our universe from something in this boy's computer? More generally, how are the laws of physics enforced?
(7) Suppose n is a positive integer, R is the set of real numbers, R^n is Euclidean n-dimensional space, and C is a closed subset of R^n. Then there exists a function f: R^n --> R so that f is zero on C, positive otherwise, and infinitely differentiable.
It is fair to say that the Mandelbrot set is bizarre, but it is a closed subset of R^2. So, the Mandelbrot set is the level set of an infinitely differentiable function. So, a very smooth function can have a bizarre level set.
Also, the graph in the plane of one dimensional Brownian motion is closed and almost surely differentiable nowhere. So, a curve differentiable nowhere can be the level set of an infinitely differentiable function.
So, could have a landscape given by an infinitely differentiable function, in a valley pour in water, form a lake, and, as in Mandelbrot, have the boundary of the lake be as irregular as the Mandelbrot set or Brownian motion. So, a very smooth landscape can have lakes with very irregular boundaries.
