@DizzyDigger Yep I do think about one sneaking up behind me. I do have my Colt in my back pack but that's useless if one is hanging off my neck. I check my surroundings quite often.
In my experience with big cats there's three primary reasons why a cat might approach you.
First, it's curious as to what you are, or what you're doing in it's backyard. If you see this cat, they are generally pretty easy to spook away from you.
Second, a mom with little ones doesn't want you in her backyard. She's going to make herself known, and she's asking you to leave, and in no uncertain terms. She will not spook away so easily, but generally physical confrontation can be avoided.
Third, you are on the menu. It is most likely that you will neither see nor hear this cat before it charges. Be prepared to fight. If no handgun, hopefully there's a sharp, fixed bladed knife in a belt sheath. If no knife, the next choice is to get an arm free and gouge it's eyes.
In those situations, I keep the thought in my head: "If you don't look or act like prey, you won't be prey."
No idea what it looks like today, but I used to hunt quail and rabbits in Fontana.
