Incidentally, I used to work in dynamics and Hagai is great to work with. To give you a sense of him, I went to a conference on dynamics that he organized about six years ago, and he opened it with the following story:
Many years ago, the philosopher Nasreddin was on his farm looking out into the distance and saw some people approaching. He had heard that there were bandits in the area and became afraid that they would come, beat him, and steal all his things. So Nasreddin ran away. As he ran, he came to a graveyard, and there he found an open grave. In case the bandits followed him, he decided to take off all his clothes, get in the grave, and pretend to be dead.
It turned out that the men were not bandits, but were Nasreddin's friends. They saw him run off and wondered where he was going and so followed him. As they were walking through the graveyard, they came upon the open grave and saw Nasreddin lying there naked. So they asked him, "Nasreddin, why are you lying in this grave with all your clothes off?"
Nasreddin opened his eyes and saw it was his friends, and replied, "My friends, there are some questions which have no answers. All I can tell you is that I am here because of you, and you are here because of me."