Pretty normal for anyone that grew up outside the city

  I was driving dads honda four wheeler by five.  Drove dads old 90 F250 by the time I was 8 and was running a tractor swathing hay when I was 10.  Pretty par for most of the other people I know.     My cousin right now is 7 and swathing with a self-propelled swather.  Though that is only when his dad is also on the field cutting and strict orders he never leaves he seat.

We didn't get a 4 wheeler until I was 14 or so. My dad figured since we had horses there was little need for one.

We got one after my horse fell with me breaking my leg, a rib and cracking multiple others. It was about a mile and half walk back to house with a gimp leg and then wait on the porch for an hour or so for dad to arrive home. No cellphones at that time so I just had to wait until someone got home.

It is not like the 4 wheeler was safer though. I flipped and rolled that thing a ton of times.

It is pretty common for anyone I know from my hometown in western OK. It seems to be pretty normal for most parts of the country in rural areas from my college friends as well. I never went on wheat harvest during summer, but most of my classmates in school did so for extra money during summer. I usually worked on my cousins fence building business for some extra cash or rode doing round-up for someone.

Swather seems to be the de facto starting implement of choice. I think since it is really nothing more than a big mower in practical function. The one we had that I learned on was a single stick hydrostatic drive model. Which is dead simple in function, push forward go forward, left to turn left, etc etc. Most of our fields that I started on were close to dead level. So I didn't even have to monkey with the head tilt/raise etc.

Well, rumor has it you don't actually "own" a horse - you just enter into an indentured servitude arrangement for the duration of the horse's life. 

Something odd I just realized...I've never driven a U.S.-made vehicle with a manual transmission.

I learned to drive stick in my dad's 1965 VW Beetle.  In college, I bought myself a 1987 VW Rabbit GTI.
At various times in high school and college, I drove my friend's 1979 VW Westphalia conversion, and his dad's 1973 Beetle.
When I was stationed in Germany, I bought myself a 1998 Audi A4.
When I was in Afghanistan, I drove a Toyota HiLux and a Toyota SUV type thing.

One thing about the various products of Wolfsburg and Ingolstadt:  the clutch take-up is STRONG.  You know when the clutch starts to grab.  It's very obvious.  Even when the engine only has 32 horses.  (1100ccs in that '65).  The clutches on the Toyotas (granted, overseas models, not U.S. market spec) were similar, if less pronounced.

On one (and only one) occasion I tried to drive a friend's early 90's Honda Civic.  Given that my whole experience with manuals at that time was with those German clutches, I could barely tell when the Honda's was engaging.  I stalled it like 3 times, just driving across town.