When you meet Robert M. Morgenthau, it feels like nothing has changed. His office on the 31st floor of Wachtell, Lipton, Rosen & Katz is as messy as ever. His assistant, Ida Van Lindt, is still with him after 44 years. The photos of him with John F. Kennedy, Martin Luther King Jr. and Lyndon Johnson still adorn the wall. And they still call him boss.