Is it normal for teenagers/adults to wear long johns

or footie pajamas, aka pajamas with feet :/ i'm just wondering cuz i used to wear those all the time when i was younger, and hey, they do make adult ones for a reason right? and i really want a couple pairs for christmas now, so i'm just wondering if its normal for big people to wear these, i see them in adult sizes at stores. not sure how to ask though but its just a thought in my head cuz when me and my mom were down stairs in the kitchen tonight, theres a bunch of magazines on the table right now and i saw a little boy wearing those in one and i asked her hey what do you think of adult long johns? and she said that sounds awesome, not sure if she was being sarcastic or not, but hey maybe she or the others in my family will end up wanting them too, so i wont feel weird :/