What is the minimum number of square meters required for a human to grow all their own food on and be self-sufficient?
Theres no easy answer as one has to consider several factors. Such factors are quality of the earth, type of plants, weather, personal skill and many more. Even the best conditions can end in unsatisfying results if one of those factors is off. 
To give you an example; When you have don't have agriculturally usable earth, like in a desert, then you need a much larger area of land to get to the same outcome than when you have high quality earth available.
I loved your answer, it has a lot of logic, but usually when you ask this kind of questions you expect someone of some kind of general parameter as an example, specifying minimally how this could be possible by making generalities of data.

Example:

1-.Define a specific crop and how big the space where it is grown could be.

2-.Define a place: where you sleep, the shelter as it is vulgarly called.

3-.Perimeter: The wall surrounds the entire terrain to be able to survive in self-sufficiency without having your crops or things stolen.
**Example:**
* **Crop:** Potatoes
* **Place:** Temperate climate with good soil
* **Perimeter:** 200 square meters

This is a very general example, as the specific amount of land required will vary depending on the factors you mentioned, such as the quality of the soil, the type of plants you grow, and your personal skill. However, this example should give you a general idea of how much space you would need to be self-sufficient in potatoes.

**Assumptions:**
* You are growing potatoes for a family of four.
* You will be using intensive gardening techniques, such as vertical gardening and intercropping.
* You will be rotating your crops to maintain soil fertility.

**Plan:**

* You will need to plant potatoes in two successions, one in the spring and one in the fall.
* Each succession will need to be planted in a different area of your garden to allow for crop rotation.
* You will also need to plant other crops, such as beans and peas, in between the potato plants to help fix nitrogen in the soil.

**Space requirements:**

* Each potato plant will need about 1 square foot of space to grow.
* You will need to plant two successions of potatoes per year.
* You will also need to plant other crops, such as beans and peas, in between the potato plants.

**Total space required:**

* 2 successions of potatoes * 1 square foot per plant * 4 people = 8 square feet
* Other crops = 2 square feet
* Total space required = 10 square feet

**Conclusion:**

Based on the assumptions above, you would need about 10 square meters of space to be self-sufficient in potatoes for a family of four. However, it is important to note that this is just a general estimate. The actual amount of land required will vary depending on the factors you mentioned earlier.