Dear Max, I feel deeply sad that you have left. Now that you are gone, I realise how much you mean to me. I regret not telling you that. I wish to repair that by writing you this letter. If I send it to Imogen and to your friends, it will reach you in some way. Your work has been a constant source of inspiration for me. It combines beauty, rigor and depth. It is fundamental, I use it every day. It will last forever. You were a great mathematician. I also want to thank you for inviting me to Australia. I did some of my best work there. You were a great host. I made many friends. I wish we could meet again. I will talk with you in my dreams. Yours, Andre