Reuse Patterns Using Capture Groupz

So, by including a ^ at the beginning, and a $ at the end, we are basically telling it the string needs to be literally this with no extra stuff? It’s a little weird, because if I’m saying “I need 42 at the beginning, and 42 at the end” it does follow that requirement still. It’s just that it takes this literally in the middle as well? Basically…“Ok I started with 42, then space, then 42, then space, then 42…but I’m not at the end! So this isn’t right!”

Just trying to parse this in my head.