Yes and no. Think about it for a moment.
When Ctesibius who lived in Alexandria in 3rd century BC and invented water organ, the hydraulis, did somebody teach him how to do it?
Who taught the author of the Robertsbridge Codex in the 14th century? There must have been some mentors from whom this composer (or a group of composers) received his training.
What about Conrad Paumann, the author of Fundamentum Organisandi in the 15th century? He was blind, yet became one of the most important musicians of his generation. Again, he was an apprentice to some master.
We can go on to later centuries, when Sweelinck, Buxtehude, or Bach were active.
That was a time before formal music schools but they all had their training from the masters.
What does it tell you about today?
Yes, you need a mentor to learn the basics.
Good news, you no longer have to walk 400 miles from Arnstadt to Lubeck to study with the master.
Now we have the Internet and we can connect with whoever we want and learn from whomever we want.
For the first time in history of humanity, geography is getting less and less significant.
When we think about it, it's not really the lack of access to a local organ teacher that's stopping us from achieving our dream, isn't it?