Run a marathon in sub-4-hours without training

This was my claim (before I started running).

I can complete a marathon in under 4 hours - without any training - at all.

There was no basis to this claim - just a simple belief that I could do it - and I still believe that would be true.

My basic reasoning was that I was pretty fit. I mean, I managed to climb Mount Fuji in jeans and scruffy trainers with holes in - without any preparation.

I never got the chance to prove my marathon claim - instead I started training for an ultra marathon.

Proving my point of running a marathon in under 4 hours would've been pretty cool. People would've given me high fives, and I'd have a smug look on my face. But that feeling would be over too soon. There would be no real long term satisfaction.
And because I would've proved (or failed to prove) a point I would've probably given up running completely.

No, I needed a long term plan that could supplement my weight-loss plan and get me fitter. And stop me being bored of life.

Full disclosure:
At the time of writing - I've completed 2 marathons - neither were under 4 hours.

And I still believe my claim was true.