I was hearing today that some in the medical field don't believe in the flattened curve as a "one-off." It will be like a roller coaster. Smaller "spikes" but also multiple ones as these shutdowns come and go (which they think they will). However, each new shutdown will be less restrictive, since once you get it, your body may be a little more immune to it. So, less infected, more freedom to move about.
Think of it as a chicken pox party. Get it over with, now we're good, and each cycle of shutdowns has less people at risk. Something to that effect.
Of course, this is still speculation, but at least it comes from verified scientists and such.
Source, and the article is apparently on the site: KFAN, Dan Barreiro Show.