Literally
Literally
[Cueball and a Cueball-like friend are walking left together. The friend turns his head towards Cueball who speaks, but is interrupted by voice from behind them off-panel right.] Cueball: I was literally glued to my seat through the entire- Off-panel voice: Hah! Off-panel voice: You mean "figuratively"!
[A crazy man walks into the next frame-less panel. He has messy hair and a messy beard. Cueball and his friend stop walking and turns toward him.] Cueball: Who are you? Crazy man: Eighteen years I've watched you! Crazy man: Waiting!
[A flashback panel. Four kids are standing around talking to each other. To the left is a girl with a ponytail and in front of her is a kid looking like Cueball - this is the Crazy man as a kid. He speaks to two kids in front of him, the one looking like Cueball, is actually Cueball as a kid, and then another kid with short black hair is standing with him. Above this panels frame, which is not as high as the other panels, there is text narrated by the crazy man. He also narrates a line at the bottom of the panel where the flashback panels frame is cut of at the bottom right.] Crazy man (narrating): Ever since that day in seventh grade when you humiliated me. Crazy man as a kid: I told him and he literally exploded! Cueball as a kid: Uh, unless he physically burst , you mean "figuratively". Kid with hair: Hah. Crazy man (narrating): Remember?
[Cueball and his friend has moved back away from the crazy man to get some more distance between him and themselves.] Crazy man: I knew one day you'd slip, and I vowed I'd be there to see you fall. How does it feel? Cueball: You are literally the craziest person I've ever met. Crazy man: You did it again! Cueball: No, I didn't.

The adverb "literally" implies that the action it describes actually happened, while its opposite, "figuratively", is used when the action it describes is being used as a figure of speech, and is not a representation of what actually happened. However, "literally" is often used colloquially as an intensifier, to mean "really" or "very", and even though many dictionaries such as Merriam-Webster and Oxford Learner's Dictionaries state that this is a valid use of the word, many people object to this usage. It is noteworthy that these dictionaries try to catalog how words are used, not whether any one usage is more valid than another.  Many might say it is more consistent to say a word such as "practically" for this usage.
In this comic, Cueball mentions he was literally glued to his seat, at which point a crazy man off-panel loudly corrects him. The crazy man declares that he has been stalking Cueball for eighteen years since an incident in seventh grade, when the crazy man (as a kid) used literally in the colloquial sense, and young Cueball corrected him. He felt humiliated and began to follow Cueball everywhere, waiting for Cueball to make the same mistake, presumably to save face.
When Cueball tells him that he is "literally the craziest person" he's ever met, the crazy man thinks that he is incorrectly using the word "literally" again; however, Cueball reassures him that he did not misuse it, meaning the crazy man actually is the craziest person he has ever met. This is reminiscent of the title text in 1652: Conditionals .
The title text points out that a chemistry experiment gone wrong is one of the few things that could cause someone to literally be glued to their seat, having previously been figuratively glued to their seat in fascination.
In this manner the title text could provide an alternative interpretation of Cueball's original sentence: "I was literally glued to my seat through the entire [chemistry experiment.]"
If this interpretation were correct, then the crazy person interrupted Cueball before he had a chance to finish his sentence, thereby never fulfilling his vow.
On a side note, if they were in seventh grade when Cueball corrected the crazy man's mistake, then Cueball and the crazy man are 30-31 (12|13 + 18) years old, approximately the same conclusion as in 1577: Advent .
[Cueball and a Cueball-like friend are walking left together. The friend turns his head towards Cueball who speaks, but is interrupted by voice from behind them off-panel right.] Cueball: I was literally glued to my seat through the entire- Off-panel voice: Hah! Off-panel voice: You mean "figuratively"!
[A crazy man walks into the next frame-less panel. He has messy hair and a messy beard. Cueball and his friend stop walking and turns toward him.] Cueball: Who are you? Crazy man: Eighteen years I've watched you! Crazy man: Waiting!
[A flashback panel. Four kids are standing around talking to each other. To the left is a girl with a ponytail and in front of her is a kid looking like Cueball - this is the Crazy man as a kid. He speaks to two kids in front of him, the one looking like Cueball, is actually Cueball as a kid, and then another kid with short black hair is standing with him. Above this panels frame, which is not as high as the other panels, there is text narrated by the crazy man. He also narrates a line at the bottom of the panel where the flashback panels frame is cut of at the bottom right.] Crazy man (narrating): Ever since that day in seventh grade when you humiliated me. Crazy man as a kid: I told him and he literally exploded! Cueball as a kid: Uh, unless he physically burst , you mean "figuratively". Kid with hair: Hah. Crazy man (narrating): Remember?
[Cueball and his friend has moved back away from the crazy man to get some more distance between him and themselves.] Crazy man: I knew one day you'd slip, and I vowed I'd be there to see you fall. How does it feel? Cueball: You are literally the craziest person I've ever met. Crazy man: You did it again! Cueball: No, I didn't.
