That's easy for Buffett to say but there is a huge difference...

That's easy for Buffett to say but there is a huge difference between an apartment versus a company share price.
Things can go wrong all of a sudden with companies whereas what can go wrong with an apartment ( barring a fire or earthquake). I don't agree. We should watch company investments like a hawk. Things can and do go wrong, sometimes quickly and badly, even in companies we thought were good. Fundamentals change.
As a famous economist once said, when the facts change, I change my mind.