i share similar views, although the line between suffering and enjoying is always in a flux and very blurry. At times, i can run relatively fast for long durations, eg. sustain below 6min/km pace for more than 20km, without feeling like unbearable. Sometimes, even at 7+min/km pace i feel awful. For me its all about how my body react in the first few km and can i breakthrough the awful feeling and feel good after that. If it doesn't by 5th km, it probably won't work for me. If it does, then i am onto something.
Previously i spoke to an ultra marathoner and he shared with me his point of view. One way or another, you will be suffering by doing your runs , fast pace or slow pace (shorter or longer duration of suffering). Hence, the crux is how your training allow one tolerate sufferings in long durations without giving up/breaking down.
For amateur hobbyist like us, perhaps its a case of how we build our foundation/base to enjoy and achieve the targets we set for ourselves. With regards to mind over matter, i do believe in it, but one needs some form of foundation to work on, eg. give yourself a last burst of fire in the last km. To do that one needs to be able to harness all the energy within oneself and sustain powerful output for the last km. Without such basis, no matter how powerful one's mind, it just won't work.
Anyway, Just work towards a better ourselves and enjoy the journey. And all the best to your new target.