Most people read the paper, watched the nightly news and that was about it.

The only 24/7 information hose was neighbor gossip.

Life is easier in ignorance. The sort of access we have into everyone’s lives now wasn’t a thing. Easier to tell stories of great men when they aren’t tweeting obscenities.

On the other hand. Nancy being his puppet master towards the end did gain traction. And rumors and myths had no easy to verify answers.

We had local news at 5, national at 530, and world news at 6. We saw what they wanted us to see.

I don't think the public knew at all while he was in office. There may have been some early signs those closest to him noticed. There was certainly nothing at the level of Rump. Regan could easily hold on to the thread of a whole sentence from start to finish.

It was considered to be a concern for the cabinet, but Reagan was functional enough to not get a 25th amendment vote. A lot of Reagan's memory issues for presented through the Iran-Contra scandal, so a lot of the public heard "I don't recall" as a legal tactic over mental deterioration. The administration was also a lot more strategic in their use of Reagan during his second term and had a far more competent cabinet to cover for Reagan.