Once upon a time, Matt understood for himself what does his long-term education and PhD means in the end. He also illustrated all that in drawings.
I am publishing this work because it shows how every person using simple visuals can make good use of visual images. The thought is deep and worth of citing it. I am translating it.
Imagine that this circle represents all knowledge of all mankind.

By the time we finish primary school, we have this amount of knowledge:

When we are done with high school, we know this much:

At university we deepen our knowledge in core subjects and also obtain a specialization:

Then we received masters in our specialty:

Once you’re at the boundary, you focus:

You push at the boundary for a few years:

Until one day, the boundary gives way:

And, that dent you’ve made is called a Ph.D.:

To you, of course, it looks a little different:

But the bigger picture looks like this:

Lets keep pushing!