The kids in Stranger Things are far from normal because they face perilous situations and monsters from another dimension with a brave face on while normal kids, and most normal adults, would beat feet at the first sign of trouble.
They see Eleven slaughter a squad of soldiers with her mind and think "yay, happy ending!" instead of "OMG I'm about to have a serious case of PTSD, after I puke my guts out".
But, as you'll see in this comic by Jacob Andrews, the biggest difference between real life kids and the Stranger Things gang is responsibility and reliability, two words that are not part of a normal kid's vocabulary.