I was getting over an injury several years back. I got Bursitis in my knees, but hadn't had it in a while. I was going stir crazy with taking it easy for so long, and felt I my healing was coming along well. Well, I decided to take a day trip in late November. It started out as a awesome trip, with mature bucks on every ridge chasing does a few miles back on a pretty easy and fairly flat hike. To make a long story short, my bursitis flared up and I couldn't lift my feet off the ground, and I needed to hike back to the truck. I was out there well past sundown with a head lamp on it's lowest setting, taking about 3 steps at a time, resting, and continuing at a snails pace. Well, something told me to turn the head lamp to it's highest setting, I panned to my right, nothing, I panned to my left and these big yellow eyes were slithering their way through the brush toward me. The cat stopped, and then continued, stopped again and lifted it's head above the brush. I've seen numerous lions over the years, but this cats head was the biggest I have seen, in the wild. It started again and was easily closing to one leap away (for the cat). I gave it everything I had turned toward it, let out a loud groan and took a couple steps (foot drags) toward it. That was the last I saw of that cat, it simply turned and disappeared. Needless to say, I left the high beam on the rest of the way to the truck, which took at least 3 more hours. Normally, I would have been back to the truck before sundown, but not in that condition.
I agree with some of the previous posters, cats are stealthy but shy creatures that generally don't want to have anything to do with humans. But, present yourself as injured prey, and they will readily place you on the menu; throw in a crying baby, and well... However, there have been several lion attacks here in Ca, on joggers and bicyclist. Simply put, the cats patterned them like they do their normal prey, set up for the attack, and followed through.