What's the reference to linoleum?
As always, genius is a good source for analyzing of song meanings. This particular song has been extensively analyzed by multiple users. Having said this, most of the time a song's meaning is subject to interpretation.
To start with, linoleum is a type of floor covering. The whole song is playing around with this floor theme. It starts with the first few sentences:
Possessions never meant anything to me
I'm not crazy
Well that's not true, I've got a bed, and a guitar
And a dog named Bob who pisses on my floor
That's right, I've got a floor
The last two lines have the following analyzis on genius:
This is a humorous line, mocking a response that would be given to someone who might criticize the protagonist for being a hypocrite or “not punk”, since technically a floor is a possession.
Not much more to add here. The singer has adapted to a punk lifestyle, where possesions are not deemed important, still he, like anyone with a home, owns a floor.
Then the next few lines:
I've got pockets full of kleenex and lint and holes
Where everything important to me
Just seems to fall right down my leg
And on to the floor
The genius interpretation:
Being a punk means keeping everything you need right in your pockets. Since you don’t have much cash, your pants are old and tattered, with holes in the pockets. Everything the protagonist places into his pockets ends up back on the friendly linoleum; i.e. it is there to catch things that are important.
In a quite humoruos way, the singer suggests that the floor offers him stability, by "collecting" things he drop.
Then the last lines before the floor themed is dropped:
My closest friend linoleum
Supports my head, gives me something to believe
And the analyzis:
This illustrates why linoleum tile is the protagonist’s best friend: it catches change and other contents of his pocket, it supports his head when he passed out on the floor stinking drunk or high, doesn’t pass judgement, and delivers hope since it’s so solid and reliable. This word play implies that the protagonist is on the floor passed out a lot from partying, hence why he’s good friends with linoleum.
No matter what, he can always count on his linoleum floor. "Supports my head" suggests that the singer is lying on the floor, probably from being drunk. The linoleum floor is there to support unconditionally, unlike human beings.
After this, the lyrics move away from the floor theme, but keeps the theme of the punk lifestyle.
So, to summarize:
To me, the song is partly making fun of the punk lifestyle, while the singer admits living that way. The linoleum part is used to give a humorous twist to the fact that, despite the fact that possesions are not important, even most punks have somewhere to live. The floor also acts as his best friend and offers him support, whatever happens.
The song is not only humorous in it's tone, it also has elements of social criticism, espacially in the second half.