In "IDK," the speaker feels they have lost track of who they are. Everyone around them, including family, friends, coworkers and partners, seems to tell them how to dress, act and behave, and they shape themselves to fit each person. The poem pictures this as being a fish in a school, pushed around by many currents. The ocean is huge but empty, which suggests the speaker feels alone even in a crowd.
The questions in the middle show the confusion most clearly. Is the speaker the obedient child, the risk taker, the hard worker, or the one who puts others first? Each role belongs to someone else's idea of them. By the end, the pressure has become too much, and the speaker is "in a hole" with "amnesia," forgetting themselves entirely. The mood is tired, bleak and quietly desperate. The plain, simple language and the repeated "I do not know" make the feeling sound honest and unpolished, like someone thinking out loud.