Last year there was a guy who did the 5K in a wheelchair and then came back the next day to do the half marathon. Not a smooth track either, got some uphills (ramps) to go with it. He was working it. Very worthy of admiration.
Goggins is entertaining. It's more tough love and stop making excuses. I guess you can be motivated by that but like grapedrink said above, if you're already driven, it's peripheral at best.
Vince Lombardi nailed it on the other hand, the greatest motivation by far is fear. Whatever you're scared of, you might lose your job, that outside set is coming and you really don't want to wear it on the head, etc., whatever it is, that will push you to dig really damn deep. And Goggins is right about the 60% rule - that even when you think you're done, you still have another 60% in the tank. Suffering is good for the soul. And what he glosses over is that you pay for dipping into that tank; make it worth it.
I apparently had Medium Covid last week and running 14 miles at about 8:30 pace last Saturday, while clearing my sinuses that's for sure, killed my joints. Couldn't even run until yesterday but the 10K felt good, smooth. Waiting for the heat to go down (currently 89 degrees out) and then jog a nice 12 miles or so. Marathon in 3 weeks but so long as don't overdo it, should be good. Goal is to keep it under 8 minute pace (7:35 would be nice but we'll see), finish under 3:30.