Like <i>jdimov9</i> I find that new places seem to make me sleep more soundly.<p>I did a fair amount of backpacking when I was younger (mostly in Scotland) which, almost by definition, includes sleeping in lots of different places - both in tents, bothies and sometimes bivouacs. I wonder if the association of being physically tired (carrying a pack all day up&#x2F;down mountains) and new places caused an association with good sleep?<p>One odd association that I have is the sound of rain  on an umbrella makes me drowsy - I&#x27;ve spent a lot of time sleeping in tents listening to rain!