Talking to a cab driver in Manhattan is often like consulting a history book: You’ll learn where the most famous residents lived, which bodega has the best breakfast sandwich and how the city has changed. That’s what happened several weeks ago when one of us was driving westbound on 45th Street near Times Square. A cab driver who’d been on the job since 1965 recalled how he would never have driven down this street in the 1970s — it was too dangerous. In fact, the first time he was robbed driving his cab, he explained, he had flagged down a nearby cop and pointed out the fleeing culprit. The cop looked at him and shrugged — something that’s much less likely to happen today, the driver said.