He was the most famous polar bear ever, being at the center of global “Knutmania,” before he died at 4 years old. It wasn’t only Berliners that fell in love with him—the entire world was moved by his story.

Knut was abandoned by his mom for unknown reasons and hand-raised by Berlin zookeeper Thomas Dörflein.

Not only was I living in Berlin back when the hype was spreading around the globe, I was riding my bike past the zoo regularly. I can remember the zoo always being busy with lines of visitors hoping to see little Knut. The tourist shops were selling post cards and memorabilia with “Knut der Eisbär” all over the city.

I didn’t get to see him in person, but always wanted to… I just never imagined that his life would be so short.

March 19 marks the 4-year anniversary of Knut the polar bear’s unexpected death at age 4.

Knut drowned on March 19, 2011, in front of a crowd of 600 visitors. He collapsed into his enclosure’s pool while suffering from dysentery. Recently an article was published revealing more details on the cause of his death after in-depth studies.

In memory of the most beloved ice bear, here are some of my favorite Knut moments. I hope they will bring a smile to your face.

1. Knut’s first public appearance with his caretaker Thomas Dörflein

2. Knut plays wholeheartedly with a blanket

3. Knut makes the cover of Vanity Fair with Leonardo DeCaprio

4. That adorable moment when Knut learns to swim (skip to 1’20)

5. Knut “dates” Giovanna while she visits from another zoo

6. Knut had a very special bond with his caregiver

Knut lost his loving “step-dad” in 2008 when Thomas died of a heart attack.

7. Knut lives on, at Berlin’s natural history museum

L’ours Knut du zoo de Berlin rentre au Musée Grévin des ours http://t.co/hhnLmpBxzU pic.twitter.com/f6f0NHc95F — Vincent Glad (@vincentglad) July 30, 2014

Knuti, as some call him affectionately, still lives in our hearts. There is a website dedicated to his fans, other polar bears, and zoo news, as well as a documentary about his life called Knut & Friends.

Hopefully Knut will somehow help us reflect on how human beings can co-exist with wild species.

In recent years, polar bears have been directly affected by climate change, which has disturbed their habit and food resources. One way to learn more about it is to check this other compelling story told by the Arctic people who know it best: the Inuits, who actually directly co-exist with polar bears.