horribly difficult and unpleasant it would actually be.I seriously doubt that he knew what he was talking about. The biggest problem in subsistence farming is the risk you take. All the knowledge you need is out there: we've been growing food for thousands of years and are still researching how to get better at it. Yes, it requires hard physical labor, but beyond that, it's not at all difficult on a small scale.
You want to have a small garden? Find a bit of land and prepare about 3'x3' of it: Dig it up, turn the soil over and make sure it isn't too sandy (add mulch if it is) or clayey (add sand if it is). If the area regularly gets flooded, then build a small wall around it and fill with dirt so you have a 3x3' raised bed that will drain properly.
Then plant one row each of squash, potatoes (for the experiment you can just cut an eye out of a potato you would eat and plant it) and tomato seeds. Potatoes go about 3" deep, squash and tomatoes about 1/2" deep. If you're in the Northern US you might need to use tomato plants instead of seeds since it's already July.
If you want to, you can build a no-effort compost heap next to it: just dump your organic kitchen waste in a pile next to the garden. At the end of the growing season, work the pile into the soil and it will get more fertile every year.
Check daily to make sure the soil doesn't get too dry (water in the evening) and pull any weeds you see. Don't do any more than this and you'll be eating squash, tomatoes and potatoes in three months. With a plot only 3'x3' it will take only a few minutes a day. It's that easy.