I’ve heard this thought in many places, in many forms:
You might have ten years of experience, or you might have one year of experience repeated ten times.
It’s a pithy way of saying that spending a long time doing something doesn’t necessarily mean you’re very good at it.
Reps without evaluation don’t lead to improvement. Practice doesn’t make perfect, necessarily. Practice makes permanent. In order for practice to make us more perfect, we have to practice with better form. When we don’t have good form, we have to look at the difference between where we are and where we could be, take a look at the gap, then cross it.
We cross the gap by practicing with better form than what feels natural to us. Usually, that feels wrong. Uncomfortable. But we grow into it.
Here’s something I suspect: You grow into a work environment in 2-3 years. You figure out that work in that timeframe. And then if you stick around longer than that (barring substantial challenge via new roles or goals) your growth plateaus. You get comfortable. You start coasting. And your experience coasting isn’t nearly as valuable.
Sure, you figured out that stack and that codebase and that team and org and that product. How do I know you can hack it in my world?
And that’s how decades of experience can effectively be a fraction of what they might look like on paper.