Nine months in character creation, eh? Then I'll bet you didn't start out with that strength ... that probably resulted after 168 more months of development. There is some relevance to BG III in this topic, because the 3d6 scores are supposed to somewhat correlate to the human statistical spread of abilities., and that gives a sense of realism to the game. It's the old "bell curve" again, where an 18 represents the top 0.5% of the population, 17 is in the top 1.9%, 16 is the top 4.7%, etc.
D&D originally tried to put some objective realism into the strength and intelligence scores. Strength is roughly 1/10 the number of pounds a person could lift in a military press, which I think is where you push a weight up over your head. So a person with a strength of 10 can lift 100 lbs overhead. That is actually pretty good in my book! Intelligence was supposed to sort-of correlate to the IQ score, although it also included memory capacity and some other ill defined stuff. If we stick to IQ, and use the standard scoring where the average is 100 and the standard deviation is 15, then if I do my math right, an IQ of 115 would be in the top 15.8% of the population, and that corresponds to a 3d6 roll of about 14. The other ability scores are much less correlated except by comparisons to real people. I've always associated high dexterity with Olympic gymnasts, though I have to say, some of that yoga stuff is just as impressive. Wisdom and charisma are very hard to nail down, although I think everyone has an understanding of them to some degree.
After you reach 18, the statistics have no more relevance to the human population. D&D 5E keeps giving you ability points beyond 18, so your fighter can end up with a 22 natural strength. You are then well outside the realm of normal probabilities, no longer fully human but infused with magic and godlike power ... until it's time to go to bed and then you are your normal self once again.
