I definitely think it's learnable. I think for many people it's a mindset. After a particularly heavy lunch, sometimes I'll get the urge to go lie down. In those cases, I can be asleep within minutes after putting my head on the pillow/couch.
The key for me is to be mindful that I'm trying to relax.
At night, I can often find myself laying awake for hours. The quickest way to fall asleep in those instances is to turn on something I find relaxing and close my eyes. Note: what I find relaxing isn't stereotypical all of the time. Recently, I've been listening to people scream at each other about online politics. Other times it's smooth jazz. Do what works for you that day.
Routines and habits are also very powerful. If you want to take a nap after lunch, try and lie down every day after lunch. After a few days of repeatedly taking a lunch nap, your body will naturally start to fall into that habit and it will get easier to fall asleep. I'm guessing habit is largely what drives the siesta culture in many places.
The key for me is to be mindful that I'm trying to relax.
At night, I can often find myself laying awake for hours. The quickest way to fall asleep in those instances is to turn on something I find relaxing and close my eyes. Note: what I find relaxing isn't stereotypical all of the time. Recently, I've been listening to people scream at each other about online politics. Other times it's smooth jazz. Do what works for you that day.
Routines and habits are also very powerful. If you want to take a nap after lunch, try and lie down every day after lunch. After a few days of repeatedly taking a lunch nap, your body will naturally start to fall into that habit and it will get easier to fall asleep. I'm guessing habit is largely what drives the siesta culture in many places.