I remember my older siblings reaction when I showed a 15 second gif and said "Whoo! That had to have taken a bit to finish." Upon Which she asks "Why? It's so short."
*Que intense stare*
"There are 15 frames per second. This gif took 15 seconds. Multiply 15 by 15 and you get 225 frames. Imagine trying to draw the same picture over and over again 225 times. Depending on your skill this can be a few minutes to a few hours. Still think it didn't take long?"