AF Tracking

So s'morning I was just playing with my camera (as usual!!) and I discovered it said "AF tracking ^", I thought "WTF?" called Alex, he said "Dunno" so I got on that Interweb and almost immediately found out. So if I switch AF tracking on.... when it next focusses on summat I switch tracking on then it stays in focus even if eg that person moves in frame it will follow them. So I called Alex in to try it, locked on him and held my camera still while he walked backwards and forwards and the "focussing here" bit of graphic followed him backwards and forewards

But just wow generally, cameras are so much more sophisticated and clever than they were 25 years ago when I got my Nikon FE2 SLR