Practical first-hand observation and experience is also the foundation of great, if not endless knowledge and benefit -- tool-making, agriculture, animal husbandry, musical instruments, scales and theory etc etc etc in all cultures, throughout human history. We've even learned -- and continue to learn --- better and better ways of fixing pot-holes! Only through direct and very practical first-hand observation and experience, though.

Did all this just kinda ^*Til_t* right outta the ole noodle, Bill?