It’s only a measure of time after it’s done. Only at that point can you know how long it took. In the same way that a 125 mile journey might take 2.5 hours one time but 2–4 hours another time, depending on a number of unforeseen variables, the same goes exactly the same of story points. You have no idea how long 125 points worth of stories will take to complete because you have no idea of what obstacles lie ahead of you. You might have a good guess, but that’s all it is, a guess.

And in response for your other response (now I’ve deleted the accidental story which after doing some reading I now see is how responses work…), that’s not at all how the human mind works. If you read up on the studies of Absolute Estimation (Time) vs Relative Estimation (Points) you’ll see how bad we as humans are at doing that. If the teams you’ve been working with are doing that, then whoever educated them on how to properly use story points didn’t teach them at all correctly. And the point is, you use story points to forecast. Not to say, this is when it will be finished, instead to say this is when it could be finished. As with most things regarding Agile, it’s a mindset change.