Lost Cause
Billie Eilish Lyrics

Something's in the air right now Like I'm losin' track of time (time, time) Like I don't really care right now But maybe that's fine
The singer feels a sense of detachment, and possibly disinterest or apathy towards the situation.

You weren't even there that day I was waitin' on you (you, you) I wondered if you were aware that day Was the last straw for me and I knew (knew)
The person who the singer is addressing was absent on a significant day, which led to the singer reaching a breaking point in their relationship.

I sent you flowers Did you even care? You ran the shower And left them by the stairs Ooh-ooh-ooh Ayy-ayy-ayy-ayy Oh-oh-oh-oh Thought you had your shit together
The person who the singer is addressing seems to be disinterested in the relationship, as evidenced by their lack of response and disregard for the flowers sent to them.

But damn, I was wrong (wrong) You ain't nothin' but a lost cause (cause) And this ain't nothin' like it once was (was) I know you think you're such an outlaw, yeah But you got no job (job)
The singer believed that the relationship had potential, but now realizes that the person they are addressing is not who they thought they were, and has no ambition or direction.

I used to think you were shy (shy) But maybe you just had nothin' on your mind Maybe you were thinkin' 'bout yourself all the time I used to wish you were mine (mine) But that was way before I realized Someone like you would always be so easy to find
The singer had an idealized view of the person they are addressing, but now realizes that they were simply disinterested and self-centered.

(So) so easy (easy) (So mm-mm) easy, mm-mm-mm, mm Gave me no flowers Wish I didn't care You'd be gone for hours Could be anywhere Ooh Ah-ah-ah-ah Thought you would've grown eventually
The relationship was one-sided, with the singer caring much more than the person they are addressing, who seems to come and go as they please without any real commitment.

What did I tell you? Don't get complacent It's time to face it now, now, now, now, now, now What did I tell you? Don't get complacent It's time to face it now, now, now, now
The singer is fed up and wants the person they are addressing to take responsibility for their lack of commitment and disinterest in the relationship.