I'm not the most electrically literate person, I know just enough to be dangerous.
We routinely lose power where I live, and have had a few ice storms where we were without power for as long as 8 days, so a generator is mandatory. I have a 30 amp double pole breaker running to a 4 prong generator outlet by the main house service, so I can run heat, a few lights, and the refrigerator when we lose power.
Fast forward to me browsing YouTube and watching a video of a guy who is making a pigtail so he can run his camper off of a big generator, it didn't have the RV plug like some do. He just used 10/3 power cord and only wired one side hot on the 4 prong plug that connected to the generator, TADA! 30 amp 120volt power.
So for $25, I can now run whatever I need to when getting ready for a trip.