I currently dual boot like this. I’m still really new to Linux but I always wondered about this meme since I didn’t have to change my boot settings other than to boot the drive with Linux first. Now it makes sense but it had me wondering for a while there!
There is also an old Jhonen Vasquez (Invader Zim author) comic where he does a bit about a “tickle me hellmo”. I always think about it when this Elmo meme comes up