For me, and I'm sure I've said this before, one of the fascinations of radio is how how signals travel from one place to another; how signals can be strong one day and almost inaudible another. I find this true at both VHF and HF.
One of the pleasures I find on HF is to listen to a band that you think should be closed and see what's coming through. That's what happened the other night. I'd had a quick spin around 28MHz which wasn't doing anything at all (it was well after sunset) so I went down onto the bottom end of 14MHz.
The band was pretty quiet - but the great thing was that the only signals coming through were from several thousand miles away. First heard was a chirpy weak one, which turned out to be from Honduras, working into the USA. I listened to him for a while and tuned up and down the band a bit, only to find a Venezuelan station at good strength. He was also working into the USA.
Though I didn't get a chance to call, I'll bet a contact would have been possible and it's often fun to surprise people with a call from far away.
Even when you think the band is closed - have a listen!