From an early life-time in the pool I have had the fortune of swimming with/ against/ observing some of the very best in the sport including a GOAT (at the time), American and NCAA record holders, World record holders, Olympic medalists, NCAA champions, a runner-up NCAA championship team (Cal) and the Swiss national team during an Olympics year. All of it before I went to university.
Starting with the easiest : Matt Biondi, a tall muscular kid from Moraga (over the hill from Berkeley) dropped, full-prime, into my sophomore year of high school when, in 1983, he stepped onto a racing block at Cal's new Spieker pool for the 50-yard freestyle final at the Northcoast Swimming Championships. With the sun blazing and the stands screaming "Bee-On-Dee", Matt went 20.40 - a national high school record.
From HS Matt went to the summer Olympics in '84, '88 and '92 winning eleven medals including eight gold. He set world records in the 50m and 100m freestyle. At Cal for college, he swam and played water polo with NCAA titles and American sprint records from the get-go.
I trained with Cal my senior year HS so Matt and I were in the changing room though, really, he paid me no mind. It was hard, for me, not to be star-struck especially when seeing him hit NCAA automatic qualifying times (top 16 from the prior year) in mid-week practice.
Also on the Cal team was John Mykkanen, a Cal freshman and with me in the distance lane. Mykkanen won a silver medal in the 400m freestyle in the LA '84 Olympics; he also set a US high school record in 1983 in the 500yd freestyle at Socals with a 4:19 only it was second-place to Jeff Kostoff who went 4:16. John had an awkward technique with one arm crossing his head on the catch-up forcing an extraordinary body contortion mid-stroke. He was also overweight which is difficult when swimming so much. But, hey, it worked for him. His daughter Courtney went to Cal and swam at the 2012 Olympic trials.
Matt Biondi at the '88 Seoul Olympics. Photo from the Cal Top 100 Athletes website (Biondi number 10).