By the age of seven, your body has fully generated entirely new cells, making it as if you are a new person.
Dear 7-year-old me,
You are still very young and not very aware the concept of money, time, and other "adult"-like things everyone should know. However, you do have a wide imagination—something every adult wishes to have. Imagination is something that should be kept and appreciated, not only does it make you unique but overall more rounded with humor as well as maturity when you grow older. I hope you can appreciate what others do for you more. Always say please and thank you, please do not ask for more junk food. (when you're 12, you will learn about over consumption of sweets anyhow) and finally, read more books. It broadens your vocabulary and expands your memory. Please continue to be social to everyone, never leave anyone out because they are not 'cool', always get your work done and keep a smile on your face. Your grandparents should be valued. Never think you are better than hanging out with elders. (that's called being a dick).
And finally, do not forget you are very lucky and loved. Always appreciate these things.