"why it is not possible to write one intentionally,"
For the same reason it is not possible to writ a hit song intentionally
You write a song which you hope might become a hit, but you have no say in whether it becomes one or not.
It would be stupid to go around claiming you have written a hit song before it becomes on - it's just as stupid to go around claiming you've written a folk song before it comes one.
" check mate jim"
??????
Jim Carroll