His fellow choreographer Jonathan Burrows had that response when talking to him about Forsythe's duet The The, which was included in a recent Queen Elizabeth Hall programme of dances. Some reviewers found The The hard to take, with the dancers sitting down all through it and making small, sometimes aggressive movements. British audiences will have a better chance to judge Forsythe's work at more length when his company at last makes its British debut at Sadler's Wells tonight.
Reid Anderson, now director of the Stuttgart Ballet, remembers dancing alongside Forsythe in the Seventies. That was when Forsythe, at 26, showed his first public choreography, a duet called Urlicht, to music by Mahler, initially dancing it himself with his then wife Eileen Brady on a workshop programme. "It was an instant success, was taken into the company repertory, and he asked me to dance it," says Anderson. "You knew at once you were working with a real choreographer from the way he could describe exactly what he wanted and how the step had to look. We still have that piece in the repertory."
Anderson sees Forsythe as "one of those really fantastic choreographers who take the art form forward...he changed the face of ballet, not only by stretching the dancers to the limit but by the way he uses music, costuming and the stage."
What Royal Ballet dancer Peter Abegglen likes about being in Forsythe productions is that he always makes dancers give "a little bit more than they think they can achieve". He says that Forsythe "changed things for us to fit our bodies, because he always wants the dancers to look good". His colleague Deborah Bull says of her rehearsals for Steptext that "he moulded it to me, and moulded me to it".
Bull likes Forsythe's work and "him as a person, his attitude: terribly straightforward and enormously enthusiastic. He is working from the base of `It's great, but you can do better', rather than the English response of `That's not it at all'."
But Abegglen and Bull both acknowledge that what Forsythe does with his own company is more complex and difficult - "scary but thrilling". This is because the dancers, steeped in his work (it may take about four years to fully acclimatise), have learned to speak his dance language, and he makes the choreographic process a collaboration. In Abegglen's analogy, "he gives them the words and they have to make up their own sentences".
Forsythe is punctilious about crediting the dancers' contributions on the printed programmes, and pays them for their share, although he makes a distinction between different levels of authorship. "If I've made the material and you're realigning it, OK you don't get paid for that, but if you're developing the material yourself and I need to use it, yes, you get paid for that section."
Reid Anderson adds that although the Frankfurt dancers sometimes have to improvise, it is within a framework that Forsythe has set. "It drives him crazy if they go outside that framework." And in his choreography they "have to remember not only what the step is but how you have to do it".
Even in the more straightforward ballets which Forsythe has created or remounted for other companies, such as the three in the Royal Ballet's repertoire, he takes the dancing out of its traditional alignment, with twists and unbalances, unexpected timing or placing, and a casual way of walking or standing mixed in with the formality of balletic movement.
The creative procedures he has developed within his own company enable him to go further in terms of complexity, of turning sequences inside out or back to front, and of exploring minute relationships between different parts of the body.
Just as George Balanchine, having established his own style of pure classic ballet as a standard for others to aim at, introduced a sharper, more angular neo-classic style in the Fifties with ballets such as Agon and Episodes, so Forsythe has gone a step further in turning ballet into a style that accords with the pace, structure and moods of the other arts at the century's end.
Whereas a conventional choreographer is the person who devises the dances, even though often with some input from the dancers, Forsythe has been writing himself out of the process to a large extent. But he is still the one who essentially has to start things off by setting the tasks for a new work, the timing, the structure, the nature of the movement to be explored; and also to bring the material together, to say no when necessary, to edit and display it, choose the atmosphere and the scenic context. So however much or little of the choreography is directly by him, the complete work remains recognisably his.
That is why it is "so very different from the things that we do," says David Bintley, choreographer and director of Birmingham Royal Ballet. He finds it "a very personal style, and a style which, for all of the philosophical background that colours each piece, is just concerned with bodies, with movements."
Bintley finds that young people are looking back at classicism, and that although Forsythe's work is light years away from the old style, it is still classicism: "There's still the pointe shoe at the back of it."
So BRB will present one of Forsythe's ballets next year, because Bintley thinks it is necessary for British audiences outside London to see this for themselves. They will do the first part of Limb's Theorem, a three- act work, part two of which (under its separate title Enemy in the Figure) is included in the Frankfurt Ballet's programme at Sadler's Wells.
Bintley says of Forsythe's own dancers: "I like the rough edge of the Frankfurt Ballet,. I like the toughness, and the feeling that they're all individual people." Anderson, too, comments on the "extraordinary mixture of dancers and styles" in the Frankfurt Ballet; the fact that they are visually a mixture of sizes and shapes, yet all have this way of appearing right, intellectually and physically.
This fits in with Deborah Bull's conviction that Forsythe's greatest strength is that he "loves to see dancers dancing at their best". And Forsythe says of himself : "I really enjoy dancing too. Just enjoy it because it feels good. I mean, is there something wrong with that? I don't see the need to give it a false earnestness. Why be so serious? You know it's dancing, which is serious in some ways, but it doesn't have to be made more serious than it is. When we're dancing we get a tremendous amount of delight."
Sadler's Wells Theatre, London EC1, to 28 Nov (0171-863 3000)