Tapping
Tapping
[Cueball is sitting at a desk, tapping various parts of it.] Cueball: Hey, I can get different pitches by tapping on different parts of the desk. Tap Tap Tap Tap
[Cueball starts tapping faster, with both hands.] Cueball: Sweet, I can do the Jurassic park theme! Tap Tap Tap Tap Tap Tap Tap
[Cueball tap the desk very rapidly, legs crossed.] Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap
[Later, elsewhere.] Megan: So, what did you do all afternoon? Cueball: Hung out.

In the first panel, Cueball makes the chance observation that tapping different points on a desk's surface results in different pitches being produced, a consequence of the desk's different resonant frequencies at these points. He soon learns that by using the pitches produced, he can replicate the well-known theme music to the film Jurassic Park . The third panel depicts that, given a lack of other entertaining stimuli, Cueball soon becomes engrossed in his newly discovered musical instrument, and his music grows in complexity.
This is a fun observation about part of human nature, to which many people can relate. Sadly, Cueball doesn't feel like telling Megan what he did, and instead, he just gives her an empty answer. Cueball perhaps feels, as Randall suggests in the title text, that he could not explain why the tapping activity was fun in its own right and not just a consequence of boredom, so he avoids having to explain in the first instance.
Other comics have shown the idea of feeling embarrassed by what one likes, to the point of refusing to admit that one likes it.  Examples are 245: Floor Tiles and the title text of 1103: Nine .
[Cueball is sitting at a desk, tapping various parts of it.] Cueball: Hey, I can get different pitches by tapping on different parts of the desk. Tap Tap Tap Tap
[Cueball starts tapping faster, with both hands.] Cueball: Sweet, I can do the Jurassic park theme! Tap Tap Tap Tap Tap Tap Tap
[Cueball tap the desk very rapidly, legs crossed.] Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap Tap
[Later, elsewhere.] Megan: So, what did you do all afternoon? Cueball: Hung out.
