Diode
Diode
[Cueball is talking to Megan. Megan holds up a diode.] Cueball: We need to talk. Megan: Okay, but first hold the end of this diode.
[They hold the diode.] Cueball: You hurt my feelings yesterday. Megan: You embarrassed me with my family last weekend.
[They are still holding the diode between them.] Cueball: I'm sorry.

A diode is an electronic component that, to put it simply, blocks current traveling in one direction, but allows current going the other way. Diodes are a common component of digital circuits, such as those found in a computer. The end that rejects incoming current is marked with a line or band of paint.
The comic is describing a common frustration in relationships. Sometimes one party in a relationship will feel that the other isn't listening to them, even though they themselves are being as open as possible. This is analogous to the function of a diode, which the comic indicates by literally introducing a diode into the dialogue. The diode introduced has the banded end being held by Cueball . This means his words are blocked by the diode, while Megan 's flows through to him; she never receives his protest, his pain, or his apology and thus does not feel she did anything wrong. Megan could possibly have used the diode as a way to avoid apologizing, but she must have known she risked looking like an idiot by not perceiving his apology, as illustrated by the title text: Megan didn't perceive Cueball's apology, due to it being blocked by the diode, so she berates Cueball for not apologizing. An alternative explanation is that Megan won't apologize, as she doesn't hear Cueball's complaint, and that Cueball is unhappy with her for this.
[Cueball is talking to Megan. Megan holds up a diode.] Cueball: We need to talk. Megan: Okay, but first hold the end of this diode.
[They hold the diode.] Cueball: You hurt my feelings yesterday. Megan: You embarrassed me with my family last weekend.
[They are still holding the diode between them.] Cueball: I'm sorry.
