you likely wont feel it til you get older. for example i have a co worker friend who never had kids and got divorced in his 40s. he recently got into a bad car accident and hes been alone in the hospital for 2 weeks.
my dad on the other hand had a room full of grandkids after his car accident.
I think there are a lot of variables here and as long as you have solid relationships with your siblings and friends and relatives and even coworkers this won't happen unless you've literally outlived everyone and at that point good for you.