I need your Help ... What to tell him?

Do what parents have done for generations, make something up!

The heat it produces doesn't stay long enough for it I guess

It's waaay too burnt up

Lightning go too fast. Go snap but no time for pop. Take 2 minute.

It doesn't have enough snap or crackle to pop.

I feel like lightning would just turn it to ash

Corn has to be very dry in order to pop, lightning would produce more then enough heat energy to pop dry corn but would also just as likely light it ablaze.

Not all corn is popcorn, popcorn is a specific variety of corn.

I thought the kernels have to be dried up first?