The most honest answer to that Reddit question is also the least satisfying one: there is no single formula that transforms how you work with data. The real transformation happens when you stop hunting for a magic trick and start asking better questions about what your data needs to do. That shift in mindset is worth more than any function in the formula bar.
The story captures something genuine. Learning basic formulas and shortcuts does make a measurable difference. Anyone who has discovered VLOOKUP or INDEX-MATCH knows the feeling of time suddenly bending in their favor. But the premise of the question, that one master key unlocks everything, keeps people stuck in a reactive relationship with their tools. They learn a trick, apply it to the problem in front of them, and then wait for the next trick. The spreadsheet stays in control. The user stays one step behind.
What actually changes the game is understanding the logic that connects formulas, not memorizing individual ones. When you grasp how a lookup function works conceptually, you can adapt it to filtering, merging, or validating data. When you see that conditional formatting is just a visual layer on top of a logical test, you stop Googling "how to highlight duplicates" and start building your own rules. The formula is the answer to a question you already know how to ask. That is the distinction that turns a passive user into an active one.
For anyone reading that thread and feeling overwhelmed by the range of suggestions, the practical takeaway is simple. Pick one formula you use regularly and learn why it works, not just what it does. Then apply that reasoning to a slightly different problem. Repeat that process a few times, and the spreadsheet stops being a collection of tricks and starts being a system you can direct. That is the transformation worth pursuing, not a single formula, but the confidence to ask your data the right question in the first place.