Today is the last day my twins are four. I wrote them each a letter on this last day of being four. Here is my letter to my son.

Dear Max,

Today is the last day you are four years old. The thought of you turning five fills me with pride, fills me with excitement, and anticipation. There is a small part of me that feels bitter sweet, realizing that you have left everything baby and toddler behind you, but mostly, I can’t wait for what is to come. I say this not for generic reasons, but I say this because of who you are becoming.

You, my four-year-old boy, are one of a kind. Yes, I say that because I am your mother and all mothers think their boys are one of a kind, but I say that because I know, like the back of my hand, who you are. You are sensitive, you have a kind heart, you have a moral conscience, you want to be good, you wholeheartedly love and care about your sisters, your grandparents, your friends, your mom and dad. You are aware and considerate of the company you are in, and you are observant and have a ridiculous memory for last summer’s vacation, last week’s Vikings game, and that time we went out for pizza and your baby sister didn’t want to eat her peas.

You are my sensitive boy that wants to hug me just a minute longer before you go to bed. You startle me in the still, dark hallway at 6 in the morning before I leave for work, “You are my favorite mommy in the whole world.” Your face falls with devastation when you get in trouble for something you know you shouldn’t have been doing. You fight back tears welling in your eyes when you are disappointed and your expectations have not been met. You can’t help but let out that pure joyous giggle when you learn about a surprise that is to come your way.

You are dedicated and responsible, which are things I am not so sure can be taught entirely. This past Friday, you had your holiday program, and you were sick and vomited on stage, then proceeded to sing and dance for an hour-long program, including starring as Mr. Turkey in Hello Mr. Turkey. And you did so, unfazed, singing and dancing in a pile of your own vomit. Unbelievable. Your perseverance is unparalleled.

You are so smart. You remember scores to football games from three weeks ago. You memorize the most obscure dinosaur species from your big book of dinosaurs. You can add. You can read. You are inquisitive and asked your dad the other night, “what was the first thing that lived on earth?” You use logic and reasoning in ways I had no idea a four year old could do.

You are gentle. You adore your baby sister and want her hugs and kisses. You watch out for your twin sister and protectively put your arm around her when you are both timid in a new situation. You tell her how she hurts your feelings when she is sad.

You love football, making crafts, playing board and card games—your new favorite is checkers. You love being outdoors, you love adventure, you love books. You love dinosaurs, superheroes, and robots.  You love to eat.

You are confident. You are sensitive. You are kind. You are smart. Your smile is infectious. Your dimples are to die for. You have the sweetest words, and I couldn’t ask for a better son.

To you, my four year-old son, on the day before your turn five. Thank you for giving us these five wonderful years with you and for giving us so much to look forward to as we watch you grow. You are my favorite little boy and I am so lucky and thankful to have you as my son.

All the love in the world for you, my baby Max.

Your mom and biggest fan forever and always.