It always comes back to The Goal Pace question. "how fast is that?", "what is that, per mile?", or some variation thereof. This is usually the second question. It arrives hot on the heels of The Goal Time question. A little math can get a person from one to the other (and back again!), but math is hard, so the questions typically go hand-in-hand.
Weather check! Ooh! It's looking colder!
So if they are the same thing, why is it that the The Goal Time answer is so much easier to vocalize than The Goal Pace answer? The Goal Time answer prompts a few goosebumps, and maybe a light sheen of sweat. Not a big deal. The Goal Pace answer though, causes mild nausea and involuntary buttcheek clenchage.
Why? It's something you have been pondering for the past couple weeks, but there's still no clear answer. The only theory (to date) which has not been shot down is that the basic assumption is wrong and they are not, in fact, the same thing. It would be difficult to argue in a court of law, but you're starting to warm to that idea. It is less scary when The Goal Pace is expressed in delta-seconds-per-mile (ΔSPMs), as in "eight seconds per mile faster than before." Maybe that's a clue.
Whatever the answer, it means this is a good goal. A good goal behaves in this manner. A goal that is known to be achievable, or one that is known to not be achievable would be the opposite of a good goal. It would be a bad goal. Bad goals leave the skin dry and smooth, the stomach settled, and the buttcheeks in their normal resting state. Nobody wants that.