You are a dear, sweet child. You have a great smile and an infectious laugh. You love to have fun, and you like using your power to make other people laugh. However, you also have a bit of a mean streak in you. You don't mean anyone any harm, but you are stubborn and a little rough. You cannot push your playmates because they want to join you in jumping around on the shapes on the rug. That is not your rug. The preschool bought it so that all the children could have fun. Those trucks are not your trucks. Just because you are standing near the truck doesn't mean that another child can't pick it up and play with it.
There is one other matter that I feel like I should address before you start preschool tomorrow. You really need to go to the restroom when you need to go potty, not just make use of wherever you happen to be standing. If you don't, they will call me to come and change you. I will not like this, and I don't think that this will help your popularity standing among your classmates either.
You like children. You have been learning to play with others and to share since you were very young. I'm not sure why you are acting as if you have never had a playdate. I know that when we went to the parent-child open house at the preschool today that you were very excited about all the toys and the fun setting, so I hope that you will take heed of this advice, so that you (and I) will be able to enjoy your couple of hours away from home twice each week.