Artist Richard Serra spent his early years after college working in steel mills. His weighty steel works sculptures are known worldwide for their raw monumentality, but unlike fellow artists Donald Judd or Mark di Suvero, Serra’s works display an aggressive edge.

In celebration of the artist’s birthday, artnet News has complied a list of five of our favorite quotes from him.

People walk among US artist Richard Serra’s sculptures “The Matter of Time” in 2011. Courtesy of RAFA RIVAS/AFP/Getty Images.

1. His big epiphany as an artist occurred when he first saw Diego Velázquez’s painting Las Meninas (1656):
“I was still very young and trying to be a painter, and it knocked me sideways. I looked at it for a long time before it hit me that I was an extension of the painting. This was incredible to me. A real revelation. I had not seen anything like it before and it made me think about art and about what I was doing, in a radically different way. But first, it just threw me into a state of total confusion.”

2. He takes inspiration from modern dance:
“The dancers were the real radicals. They taught me more about space and movement and gravity than anyone else.”

3. He once played a prank on Robert Rauschenberg:
“Rauschenberg came up [to Yale] as a visiting critic. Being a bit sparky back then, I thought I’d see what he was made of. I found a chicken and tethered it to a rope and put it in this box on a pedestal. It was a kind of prank at Rauschenberg’s expense right? But when he lifted the box, the goddamn chicken flew up above him and start shitting everywhere. That incident sums up my attitude: I don’t give a shit but I care quite a lot.”

4. He has a no-nonsense take on life:
“Your life’s a nanosecond; if you have contribution to make, then make it. Don’t bitch about it, just do it.”

5. He’s against the idea of the art star:
“It was the exact opposite of now. These days it’s all about selling, all about the market value. Sometime in the Eighties artists became Hollywood-Style stars. The personalities started to take precedence over the work.”