United Kingdom, April 18 -- Matthew Lawrence will "never forget" late 'Mrs. Doubtfire' co-star Robin Williams' advice not to take drugs.

The 45-year-old actor appeared opposite the late Hollywood star - who took his own life August 2014 at the age of 63 - in the 1993 blockbuster comedy, and in hindsight, he wishes he'd headed the warning after battling substance abuse.

He told Entertainment Weekly: "He really explained his life to me and really brought me in and taught me not just about in front of the camera, but a lot about the behind the camera as well, and how he felt that substances really further pushed his brain to not function properly.

"And he really opened up with me, and I'll never forget it.

"There were times he would just...