My changing mindset during long-distance running...

Around 4km... I still have 31km left to go, so why am I even counting? Just run...
Around 12km... Starting to get a little tired... I'm not even halfway until 18km, am I tired already? Just run...
Around 18km... This is where the mental gymnastics begin. If I go just 5km more, it's 23km. Once I hit 23km, I'm almost there, almost there. Let's hang in there just a bit more...
Around 23km... My legs are just about to lock up... Once I hit 28km, I'll only have 7km left...
Around 28km... I want to go home and my legs feel like lead... I can see the Han River starting to appear, so I try to pull myself together again...
30km... From here on, I'm counting every single kilometer...
35km... A sense of liberation surging to the top of my head. Let's go home T_T...