Yep, a good friend of mine only shot a high 500 series the night that he shot his second 300 game. He struggled badly during the first and second game, made a radical adjustment on the last ball of game 2, then proceeded to take it off the sheet in game 3 for 300.
And, I know of a lady in another town nearby who was averaging sround 143.....she shot 149, 150, 300, for a 599 series. When they asked her what her next goal in bowling was, she remarked "to shoot my first 600 series!". I talked to the fellow at the desk about the 300 game, and he had a very good view of it since she was bowling right out in front of the control desk. He said that she was all over the lane with the ball in the 300 game, rarely hit the pocket, threw the 12th ball dead through the nose, yet she carried all 12 strikes that game! Basically, it was just her lucky night.
But, a 300 game in a 476 series??? Now that's really pushing the envelope there.