IIRC, my art teacher, for a core requirement course I needed to take in college, would say Paul Cezanne got that ball rolling.
The Bay
Your teacher probably has it right. I am just a fan. I think I remember reading that Picasso and Braque's cubism was heavily influenced by Cezanne.
You can actually see the Cezanne influence in Braque's Viaduct at L'Estaque...
My grandmother suffered from Alzheimer's or premature senile dementia as it used to be called. She lived in my home and was cared for by my parents.
I saw the pain...but because I was a child, I couldn't fully comprehend it. To me, it was just a thing to be handled. It had its bad aspects and its good ones.
The good one was (before the debilitating effects arrived) that my grandmother saw life very differently. She saw the beauty of little things (and art). What was amazing was while she was losing consciousness she was gaining another life skill...that of seeing the power of life as it surrounds us.
At some point she ceased to exist as a functioning human, but she started functioning in a different realm of observation of and sensitivity to this thing we call life. Not altogether a bad thing. And she sang and whistled 'til the very end.