Turns out Colin Farrell's affable appearance at the opening ceremony of the Special Olympics in Shanghai, China, earlier this month had an extra resonance. The former hard-partier-turned-low-lying, deep-pocketed friend-of-the-downtrodden reveals to the Irish Independent that his 4-year-old son James (mom is ex-girlfriend Kim Bordenave) suffers from a rare neuro-genetic disorder known as Angelman Syndrome.

"With my son the only time I'm reminded that there is something different about him -- that he has some deviation of what is perceived to be normal -- is when I see him with other 4-year-olds," Farrell, 31, explains to the paper. "Then I go 'oh yeah' and it comes back to me. But from day one I felt that he's the way he's meant to be."

The syndrome, according to our minute and a half of Wiki research, can include developmental delays, a halting walk, speech and balance difficulties and seizures, along with frequent bouts of laughter.

The actor, who credits Bordenave for getting James into treatment early on, tells the paper he's "incredibly blessed to have him in my life," kvelling of the "amazing courage" of his "incredibly happy boy," who has only recently found his footing.

"He took his first steps about six weeks ago and it was four years in the making," says the proud pop. "All the work is his -- he worked his arse off for four years. And when he took the first steps it was incredibly emotional, there wasn't a dry eye in the house."

Farrell, who has reportedly introduced James to his current girlfriend, Dublin college student Muireann McDonnell, believes his job is to help his son achieve his "individual potential" and be "as happy as he can be."

He also says his longtime involvement with the Special Olympics, which began shortly before James' birth, helped him understand his son that much better.

"It's mad the way the world works. It's bizarre. I experienced the overwhelming effect of being around those athletes pretty much just before my son was born with special needs," he says. "I have never thought of my son as being someone with a disability. It goes back to special needs and what is a disability and what isn't."

Next: Mad Money: Brangelina's $2 Million Art Buy?