I'm curious to see a variety of people's responses to this and how much you improved since you started running.
First - what would you consider to be your baseline athletic talent/natural ability, off of no training at all.
Second - What are your various PR's, and how much training did it take to get them?
For example, I ran a 5:58 mile in middle school off of no training whatsoever. My first cross country race was something like a 22:00 5k, off of no summer training at all and like 3 days into the season. So pretty good compared to the general populace, but pretty slow compared to the pool of competitive runners out there.
Best high school 5k was 18:40. Never ran a lot of 5k's after high school, but I got the 5k down to 17 flat off of ~60 mile weeks, and ran a 4:25 1500, though I feel like I was in shape for about 16:30 and 4:15 if I'd run either of them more than twice.