Nirvana frontman Kurt Cobain died at the age of 27 when he shot himself in the head. The singer struggled with heroin addiction and depression. 

Cobain, who was born on Feb. 20, 1967, would have marked his 50th birthday Monday. It's been 23 years since Cobain's death, but several conspiracy theories about his suicide continue to do the rounds. Some believe that Cobain's wife Courtney Love hired someone to kill her husband, while Tom Grant, a private investigator, claimed that Love and Michael Dewitt, her live-in nanny, conspired to kill Cobain.

In 2012, private investigator Max Wallace, who worked with Grant, said that someone may have injected Cobain with a fatal dose of heroin before the gunshot. 

"The forensic pathologist we spoke to said that there's no way this guy could have injected a triple lethal dose of heroin into his system, then rolled down his sleeve, put away the drug kit, picked up the shotgun and shot himself. He would have been incapacitated within seconds,” Wallace said at the time.

Below is a list of 15 quotes by the Nirvana singer on music, drugs and life, excerpted from BrainyQuote and other interviews.

1. “I’d rather be hated for who I am, than loved for who I am not.”

2. “All drugs are a waste of your time. They destroy your memory and your self-respect and everything that goes along with your self-esteem. They make you feel good for a little while, and then they destroy you. They’re no good at all. But I’m not going to go around preaching against it. It’s your choice, but in my experience, I’ve found they’re a waste of time.” - Rolling Stone interview (April 1992)

3. “Wanting to be someone else is a waste of the person you are.”

4. “If you die, you’re completely happy and your soul somewhere lives on. I’m not afraid of dying. Total peace after death, becoming someone else is the best hope I’ve got.”

5. “If I wouldn’t have found Courtney, I probably would have carried on with a bisexual lifestyle."

6. “I never wanted to sing. I just wanted to play rhythm guitar -- hide in the back and just play.”

7. "I'm a spokesman for myself. It just so happens that there's a bunch of people that are concerned with what I have to say. I find that frightening at times because I'm just as confused as most people. I don't have the answers for anything."

8. “I like to have strong opinions with nothing to back them up with besides my primal sincerity. I like sincerity. I lack sincerity.”

9. "I really haven't had that exciting of a life. There are a lot of things I wish I would have done, instead of just sitting around and complaining about having a boring life. So I pretty much like to make it up. I'd rather tell a story about somebody else."

10. “I started being really proud of the fact that I was gay even though I wasn’t.”

11. “Rap music is the only vital form of music introduced since punk rock.” 

12. “I wanted to have the adoration of John Lennon, but have the anonymity of Ringo Starr. I didn’t want to be a frontman.”

13. “When I listen to ‘Nevermind,’ I hate the production, but there’s something about it that almost makes me cry at times.”

14. “I bought a gun and chose drugs instead.”

15. “I definitely feel closer to the feminine side of the human being than I do the male -- or the American idea of what a male is supposed to be. Just watch a beer commercial and you’ll see what I mean.”