There was a time not too long ago when it was pretty much a given that you could turn on the receiver, tune around in the same, limited area and hear multiple conversations going on. I think a lot of folks who got into AM in the last decade or so just got use to someone else always starting the party for them and being able to drop in and leave at their leisure.
If current activity on the bands is any indication, those days are gone. Between competing interests from family to the internet, and plain old attrition in our ranks, at times it seems more like a ghost town on HF. I think part of this is a result of so many people who 'listened, but didn't hear anyone'.
One thing that was true then is just as true now: activity attracts more activity. When a number of us moved down into the 80m frequencies after the phone bands were expanded, others followed. When the regulars stopped showing up activity waned, but you can still find remnants most days around 3.705, 3.715, and 3.725 where the guys north of the border hang around.
You'd be amazed how fast the band fills up with a few folks calling CQ on a few different frequencies. So many listeners, so few calling. Though there have been times my CQs went unanswered, at least 95% of the time someone comes back. Folks want to work somebody, they've just lost or never had the ability to call CQ. They focus on waiting to hear someone to work.
As the Nike ad said,
Just Do It. Especially now with so much activity on the high bands. Especially when you get the 610E on the air. That thing will bore a hole through the aether for you.