1, 4, 7 are all variations of 1.
They're slightly different starting points for a (seemingly) similar pattern.
They even look like variations of 1, each of the numbers - with added or morphed elements.
"I am the Alpha and the Omega, the Beginning and the End, the First and the Last.”
"I am the way and the truth and the life. No one comes to the Father except through me."
Meaning that nothing ever occurs without following the ingrained principle, or destiny, of our world. Everything is made predictable and deterministic due to this pattern (1-9) - except for the things that lie beyond the pattern (conscious realignment).
Here's your cheat-sheet for the material plane, Jim-bob:
123 = 6
456 = 15 = 6
789 = 24 = 6
11 is 2 without the pattern. Unfolded.
22 is 4 without the pattern. Unfolded.
33 is 6 without the pattern. Unfolded.
All 3 depart from the standard pattern. For the standard pattern, they're dissonant elements.
They are the symptoms of the unseen "0"-s (these are portals) that occur in three-dimensional space.
This is the new pattern being created, one that goes beyond the three-dimensional.
But even the new pattern must abide to the Rule of Threes - that's why there's three of them, because they can only be three.
But don't let all this make you go mad now.
Chocolate still tastes good, and ice cream is a thing.
Knowledge is to be had but so is enjoyment, softness, lightweight living.
Don't go burning out your psyche, just take the knowledge that comes.