There's a song by Aussie band Divinyls called Pleasure and Pain which I sing on long days in the saddle.
The chorus goes - "It's a fine line between pleasure and pain - you've done it once you can do it again - whatever you've done don't try to explain - it's a fine fine line between pleasure and pain."
It really sums up the feeling when you're searching for the motivation to finish a tough day.
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