You were a STEM major, yes, DF? If so, you come already equipped with reasoning skills (which I assume is evidenced by the fact that you aced the SAT-M?).People aren't going from average reasoning abilities to top 1% by just taking a test over and over.
However, there are average reasoning skills and average reasoning skills, and by that I mean that some majors teach them, most do not. One needs reasoning skills to do well in HS Geom - but not Alg I, and for Organic Chem (as well as for most Engin. courses). However, 'Studies' majors can skate by with little/no reasoning skills. It's not that such folks don't have an innate ability for 'reasoning', but doing well in college just don't require the use of such skills in many majors.
Thus, prepping for the LSAT is not always punching above one's weight class, but just training the brain to use it's innate ability.
Thought about another way: someone with an average IQ of 100 has neither the innate ability nor the processing speed (think pc-RAM) to clear 170. Such a score is impossible for that person. But someone with an IQ of, say, 132 (top 5%?) has both the innate ability and the processing power to get to ~170. However, they may need to brush up/strengthen/train their reasoning skills to get over 165.