The group surrounding George Brett before the Kansas City Royals played the New York Yankees one night last week recorded his words with disbelief and weak laughter. Surely he jested.

"I thought I was outclassed and would never make it in professional baseball," said Brett, the Royals' third baseman, who has a .316 career batting average and is off to a .460 start this season.

"I signed in a group that had just three of us high school players and we were up against 21 college players," he said. "That made a big difference at that time of my life. I made stupid mistakes, and they didn't, and I thought, 'I'll never make it.' "

He did, of course, and at the moment he is making the art of hitting--he refuses to recognize it as a science--seem easy, breezy and something akin to a birthright.

As of Friday, Brett led the American League in several categories of offense, a close second in a few others.

He led in batting average, runs batted in (20) and runs (18). He was second in hits (29), with at least one in each of the Royals' 16 games, and had a 22-game hitting streak dating back to last September.

Most of his hits were for extra bases--12 of 15 in one stretch. Brett had five home runs and led the league in doubles (12) and total bases (58).

He has talked of being in a trance, of unchecked confidence and, above all, of a "groove" in the basic components of the swing he has developed in a career entering its 10th year.

"The only bad thing about my swing right now," Brett said, "is that I can't stand back and watch it."

He has base hits to every field, from the corner in left to the corner in right; from the seats in left-center to the upper deck in right-center.

"When Abner (Doubleday) put them on the field in nine different positions, he left it up to the batter to hit it where they're not," Brett said. "So far, I'm doing that a lot."

When Brett hit a pitch to almost the most distant part of Tiger Stadium in Detroit--one of three home runs that night that produced a club-record seven RBI in an 8-7 victory--teammate Paul Splittorff commented, "Anything that travels that far in the air ought to have a stewardess on it."

"Fundamentally," Brett said, "I couldn't be more pleased. I didn't know what to expect, coming out of spring training on a two-for-32 slump. But things start snowballing, and the snowball is getting bigger and bigger."

So are the crowds around his dressing stall every night.

An omnipresent press corps was something he began to disdain the past few seasons, starting with impatience during the September of his pursuit of .400 in 1980. He finished at .390.

By the end of 1981, which brought a tumble from the World Series to the American West basement for the Royals, the players' strike and a disenchanted Brett, he checked and found his fun in baseball was running a couple of quarts low.

That carried over to 1982, when he said he was unhappy with his new contract, worth $5 million over five years. Last winter, trade talk surfaced from Brett's brother Bobby, who handles his business affairs.

"That's all water over the dam," Brett said. "The game is no fun with distractions, so I'm not allowing any. Nothing is going to bother me.

"I want nothing now but to have a good time, keep my mouth shut and my foot out of it, and keep hitting. I'm blocking everything out to where it's me, the pitcher and the ball, and the ball looks big right now.

"Really big."