I started shooting when I was about 4 years old.
As soon as I was tall enough and strong enough to work a reloading press handle, I had to help with reloading. With 4 boys, our dad's AR (Colt SP1) saw a lot of use. Keeping up with the demand warranted a lot of time at the reloading press. I think the first time I was enlisted for the job was when I was about 6 years old, charging cases and seating bullets for .223 Rem, of course.
So, for me, it's nearly a "What came first? The Chicken or the Egg?" kind of situation.
I know most people probably raised an eyebrow when they saw "6 years old". But, I must say... our father absolutely drilled safety checks and precision into our heads. Not once in the entire time we kids were reloading, did one of us load a squib, load an over-charge/double-charge, miss a primer, seat a primer sideways, or crush a case ... for any cartridge. And, we reloaded everything from 9mm to .44 Rem Mag, from .223 Rem to .375 H&H.
"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."