There are many levels and interpretations of 'crazy'.

The best way to sift through it all is to remember that
anyone who intends 'harm/violence/malice/etc' to themselves, others, to environment, etc - is REALLY crazy in the mind... unfit to think rationally, reasonably and is expressed in erratic, contradictory and abusive behaviour.

The other 'polite' crazy is just acting silly, an adult taking time out to have fun with the kids, falling in love, etc.

Many 'nations' are the above 'crazy'.
Nations are like people. Some have really lost the plot and intend harm to others and themselves.
War & Suicide are sure signs of 'crazy'.

Many people experience the double-helix effect.
Where they are highly sane/enlightened about one aspect of their life, but are crazy/insane in regards to another.

Scott of the Antarctic was sane in regards to his marriage.
But insane in regards to the expedition on the frozen continent.
Admundsen was the reverse.

Can't win em all - that's just plain 'crazy'