I know for myself I'm always thinking "Ehhhhh 2 seconds a mile for this half is all I need to do for my goal time? That's easy!" Even though I know it's not haha I agree, it can be easy to get that idea into your head and I doubt professionals are immune to it.

I have high hopes that Tola will become a star marathoner, although I am doubtful we will see a marathoner of Kipchoge's caliber for a while. Jakob Ingebritsen, a phenomenal 1500m and 5k runner has expressed interest in future marathoning, but I imagine he has a lot still to achieve on the track before making the move.