Besides the couple of times I got to play with a pro (Gary Hallberg 18 holes, and Miguel Jimenez 1 hole), the best golfer I played with was a co-worker. I would say this guy was 30 years old at the and maybe 5'-10" and 150 pounds. This was the company golf outing in scramble format. I was probably a 10 to 12 HC at the time. This was before I got serious about the game. I had heard that this guy was good so my league partners we quick to sign him up to our foursome.
I had heard that he QB'd his high school football team and took them to the state title. I think he might have also been a BB and baseball star there as well. This was a small country school, but he came with a reputation. A lot of this I found out later after the round.
On the driving range he displayed a smooth swing and was cracking them out there real good. I assumed that he had played on the golf team in HS and had taken lessons, etc. He said he did not play in HS. This guy was now married and had small children. There was no way he was out playing all of the time and honing his game.
On the first tee he smacks one out a lot farther than I had ever been on this short par 5. We use his drive of course. I think we were line 180 and I have my 4i out. He takes a 7i and puts it on the small green.
The only other hole I remember clearly was hole 5, which is another par 5 that has a big pond in front of the green and is definitely a lay up situation for mortals. He hits a beautiful, effortless drive which has to be over 300 yards because we had about 200 yards to the pin. Now this is a public course that probably doesn't see as much water as some in late summer, so I am sure he got some roll out.
The green has a huge slope downward from a high at the back to a low at the front, which is protected by water. There are also trees blocking the right side of the green, which if you clipped a branch you would end up in the water. If you are long you would have an impossible chip that would roll through to the front and into the water.
This guy pulls out a 6i and puts it to with 5 or 6 feet and then putts it in. The putt must have broke a foot. This guy eagles the hardest hole on the course himself. For me at the time bogey is miraculous. Today I would be satisfied with a bogey and ecstatic with a par on that hole as a 5.6 index.
Sorry for the long-winded post, but this was an eye opener for me as this was a guy that golfed less than most of us and could outplay most of us. It wasn't about technique, practice, equipment, etc. It was all about god-given athletic talent and ability. I am sure there is something about mental composure and being a competitor as he took a team to a state title. But I knew then and there that I probably would never be able to play as well as him no matter what I did or how hard I worked. He was a natural.
So to reinforce my point above, if you are a great athlete then scratch (or better) in 18 months (or less) is definitely possible.