I was also diagnosed with a duodenal ulcer when I was 10. In my case, it was the late 1980's and the H. pylori cause of ulcers wasn't accepted or widely known.
I spent a week in bed in excruciating pain, throwing up blood regularly. The doctor visited a couple of times, I'm not sure what he told my mother, but it was a week before he agreed I should go to hospital.
At that stage I was severely anemic and had peritonitis. I ended up in surgery to have a third of my stomach and some of my small intestine removed. A couple of weeks in intensive care and another few weeks in the children's ward before I was strong enough to go home.
When I left, I was told that I shouldn't eat acidic or spicy foods, and that I had an ulcer because of stress. I was 10, and I can tell you, while we didn't have a whole lot, I was far from being stressed.
Nearly 40 years later that surgery still impacts on my life. I still have some digestion issues, but knowing that Warren's & Marshall's work has prevented others from repeating my experiences has been some comfort.
Good on your doctor for trying something experimental which had such a great outcome.
The issue isn't that the grid can't handle large amount of renewables, it's that renewables aren't consistent.
Large thermal plants provide inertia that renewables simply can't provide. A lot of the work around incorporating renewables into grids is around the provision of synthetic inertia and how to manage sudden drops in supply.
Battery storage is one solution. Better demand response solutions backed by energy markets that incentivise the participation of large numbers of energy users is another.
Grids that have a high level of interconnection with other grids also reduces the impact of inconsistent supply, but not every grid has enough inter-connections for that to be a viable full solution. (See ERCOT in Texas, AEMO in Australia, Eirgrid in Ireland for examples)
Here in Ireland, we frequently run the grid up to 80% renewables, but the grid operator only does that because they have the mechanisms in places to handle sudden drops in supply.