Lyric discussion by Androgyne 

Cover art for Bummer lyrics by Monster Magnet

I can see the drug interpretation of this and I like diemundave's interpretation, but if you think about the lyrics literally, then it seems to also maybe be about a kid that's grown up not knowing his father and thinks Dave is his dad.

"You're looking for the one that fucked your mom, it's not me. It's not me."

Dave isn't the father.

"You're looking for the one who made you cry, that's not me. It's not me."

Again Dave explaining to the kid that he's not the one who left him.

"If you want to stuff your garbage in that hole, oh, baby I'm your man of the hour."

Dave's saying, "If you want to do drugs, then I'm your man."

"You think the world's got the evil eye on you, that's not true. That's not true."

He's telling him that the world isn't really against him or out to get him like he thinks it is.

"The only one I see causing major pain is just you. It's just you"

He's telling him his problems are his own fault.

"If you want to spank your demons and make 'em pay, then baby I'm your man of the hour."

If he wants to exercise his demons through drugs or whatever, then again, he's his man.

"Some people go to bed with Lucifer, then they cry when they don't greet the day with God."

I think this is about the mother. She had sex with some guy that wasn't the father type and now she's bitching about it.

"I know life's a bummer baby, but that's got precious little to do with me."

Basically, he knows life sucks, but it has nothing to do with him.

"You think you've found the one most like yourself and that's me? Yeah that's me"

Most like yourself meaning that the kid went out looking for his father, so he started by looking for someone who resembled him and possibly acted like him too.

"You're sure we've known each other all our lives? That could be. That could be."

He's questioning him, but saying that, yeah it's possible at the same time.

"I needed a small vacation, so they put me on a train. They called it "rehabilitation," oh, but here I am again. It's against my second nature not to chase you down that hole. I need a fistful of medication, just to keep it in my pants."

I think this part is about Dave's struggle with drugs, but also lust, as referenced by the "keep it in my pants" part. This part I think is saying that he would need all kinds of medication to not chase women. Which relates to the rest of the lyrics because the whole songs about this kid who's looking for his dad and Dave's saying he isn't the father, but he's a lot like him because he has one night stands and leaves too.