River Phoenix's Mom Remembers Late Son on His Birthday: 'He Is Very Much Alive in Me'

Arlyn "Heart" Phoenix is remembering her late son River Phoenix on what would have been his 53rd birthday.

On Wednesday, Heart shared a touching social media tribute honoring the oldest of her five children. “August 23, 1970...one of the most amazing days of my life...bringing Earthbound a living being...truly a touch of the most sacred,” his mother began in an Instagram post. 

The candid photo, which appeared to be taken in 1988 based on the timestamp, showed a young Phoenix with a guitar hanging from his shoulder. He loved the instrument and was skilled at playing. Heart noted that the Stand by Me actor was close to his siblings, embracing them all “with his humor, wisdom, authenticity, talent, compassion, vulnerability and undying Love.”

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“I would say he was and still is our greatest teacher,” Heart continued. In the post, she reflected on the greatest pain she’d ever felt in her life, admitting that although they were on opposite sides of the spectrum, it would be childbirth and “the pain of my son's passing.”

Despite her grief, Heart noted that Phoenix's time on earth left a meaningful impact on those who cared for him.

"The gifts that he brought were imbued in each of us and so we carry on celebrating his life for those 23 precious years,” she wrote. Heart ended her tribute by mentioning that three decades after the tragedy, her first born continues to inspire her.

“I am in awe of the fact that he is very much alive in me. Thank you for all the precious messages that I have received through these past 30 years 💖🙏💖,” she concluded.

River died on Oct. 31, 1993 at the age of 23 due to a drug overdose at The Viper Room venue in West Hollywood, California. His younger brother, Joker: Folie à Deux actor Joaquin Phoenix was with him at the time. 

On Wednesday, his younger sister Rain Phoenix also paid her respects to her late older sibling. “Happy birthday River🩵,” she wrote on a social media post.

Rain's post included two photos. The first was a black-and-white portrait of the Running on Empty actor in his adult years. The second showed the two sitting together, smiling as children. 

In October 2019, Rain spoke with PEOPLE about how she copes with Phoenix's physical absence. She shared fond memories of her brother, describing him as “the most generous person that I know and always very much concerned about the quiet person in the room or the person who was misunderstood.” Phoenix was known for speaking up for others who may have been too afraid to speak up for themselves, River said.

When asked what it was like to have him as a brother, Rain said that he was “very protective” before reminiscing about his creative side. “I think he probably taught all of us a few chords on guitar and hoped that we would follow his lead," she said. "He was such a great older brother."

Rain said Phoenix was “a master Tabbouleh maker.” The musician said her family would eat the salad for “dinner, lunch, breakfast” and that “Joaquin is a master Tabbouleh maker as well.”

When Joaquin accepted the Best Actor Oscar for his role in Joker at the 2020 Academy Awards, he recited lyrics that his late brother wrote at 17 years old. 

"I've been a scoundrel all my life. I've been selfish. I've been cruel at times, hard to work with, and I'm grateful that so many of you in this room have given me a second chance," Joaquin told the audience. "And I think that's when we're at our best, when we support each other. Not when we cancel each other out for past mistakes, but when we help each other grow, when we educate each other, when we guide each other towards redemption. That is the best of humanity."