Little kids say things like this, and although it's hurtful you have to try not to let it get to you (besides, if he knows it hurts you then he'll start saying things like this EVERY time he's mad). He doesn't really love Grandma more than you. Grandma may seem more fun since she probably does Grandma-type things like bake cookies and bring presents -- what kid doesn't love that?
Grandma also isn't responsible for discipline, or getting him to eat his veggies, or making sure he goes to bed on time. Grandmas get the fun stuff, and that's why they're great. Moms and dads get the real work of parenting, both the good and the bad.
I think your little one is just being a normal boundary-testing preschooler, and you're probably not doing anything wrong. In fact, it sounds like you're a very attentive parent, one who values and validates your child's feelings while not being a pushover or letting him get away with bratty behavior. The boundary-testing probably stems from his little brain growing so fast and learning so much, and he's discovering all sorts of new things he can do but needs to know what the limits are to feel secure.
You're providing those limits, which may make you The Destroyer Of Fun at times, but he needs that every bit as much as he needs your attention and love.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.