The following video is 19 seconds in duration, but it will put a smile on your face for the next 19 hours.
It features a three-month old boy hearing a (fake) lion roar for the first time, courtesy of his mother and a children's book, and initially reacting with fear and confusion.
But once the sounds ends and he realizes he's safe? We're treated to the magical sound of pure baby laughter. Is there anything better in the whole wide world?
And now as a GIF:
Relive some memorably adorable kid reactions now: