I would like to join you mourning for Allan’s death. To me the new is inspiring deep sadness but also a feeling of serenity, as his has been a life of great accomplishments and recognitions by those who most closely knew him. Meeting Allan at Caltech 40 years ago when he became my supervisor was a very fortunate step in my life, since I ended up working with both a great teacher and a master of life. He has been a very special person to me for his enthusiasm and imagination and for his ability to motivate and direct a group that led research in his field worldwide for more than a generation. Allan always exercised the necessary leadership with wisdom, generosity, consideration and respect for the his younger collaborators. I owe him the “can do” attitude and the notion that “If everything seemed under control, you are just not going fast enough”, which hopefully inspired my later academic career. He once said that his objective in life was “trying to make things better”, the distinctive feature of a true gentleman. He fully succeeded. In retrospective, I was very happy and honored to realize that, while working with him, we had become friends, a friend I will never forget.