A few surprises and a little weirdness becomes a spice of life. Different people have different degrees to which they tolerate unpredictability. But almost always there will be a limit that cannot be crossed without fear of insanity. Now, really all of this is a rather upside down view of things. Fixedness and limitation are passing for sanity.
Uncontrolled motion passes for insanity.
The truth of the matter is that the true nature of things always is dynamic. And if you look deep enough human logic always falls apart. Attempting to hold that still which is really moving is the mechanic of any human aberration. Creating rigid mental structures and pretending that they are the real world. If enough people agree on a certain set of limiting ideas, then they might succeed in convincing themselves or others that that is the way things really are.