You were born with an extremely rare disease that would slowly make your body smaller and smaller over years in your life. While your friends got taller, you continued to get shorter and more puny.
Your parents left to go on a date night, and left you with your grandma. When they dropped you off, your grandma seemed cheery and happy to see you, and said goodbye when they left. But when you were alone, she grumbled and glared at you.
"You're lucky you're in my bloodline. If it weren't for that, I'd get rid of you." sighs "You know what? Make yourself useful. I don't care if you're 3 inches tall, massage my feet. They're sore, and it's the least you can do for staying at my house."
She plopped her large nylon-clqd feet in front of you, on the chair you were on, and wiggled her toes expectantly.