In the summer of 2013, Jadon Sancho was with Watford's academy and 13-years-old, when one training session saw his age group paired with the 16-year-olds.
A daunting prospect for any youngster, surely, but then Sancho was no ordinary youngster.
As Louis Lancaster, his youth coach, recalls: 'If you've got someone who's going to be a top player then he needs to be outstanding in his own age group.
As a child, Sancho played above his age with older boys but was still the most gifted
'If they play the age group above, they just need to be good.