Wall Art
Wall Art
[White Hat and Cueball are standing together and looking at eleven framed pictures on a wall.] Cueball: Getting older is so weird. 20 years ago, I thought thumbtacked Pokémon posters made my wall look so cool.
[Cueball has his hands raised up in a close-up.] Cueball: But these days I feel this compulsion to get framed oil paintings and spend hours carefully arranging them.
[Return to the setting in the first frame.] White Hat: These are all oil paintings of Pokémon. Cueball: Look, I’m meeting maturity halfway.
This is the only xkcd comic ever where the year when the comic was published, in the Gregorian calendar, is the same as the comic's number. This comic is numbered 2018 and was published on Wednesday, July 11, 2018.

Pokémon is a media franchise managed by The Pokémon Company, which started with the release of the first video games, Pokémon Red and Blue , for the Game Boy in 1996. Originally released in Japan as Pokémon Red and Green , the game was released in North America as Pokémon Red and Blue in 1998, 20 years ago at the time of publishing.
This is another comic about getting older. Cueball mentions that he thought Pokémon posters were cool 20 years ago (when Pokémon was first released). Now that he is older, he instead has framed oil paintings, which were what wealthier older folks were displaying on their walls at the times that their teenagers were widely into Pokémon. The punchline comes when White Hat mentions that his oil paintings are just paintings of Pokémon characters, showing that Cueball hasn't completely adopted those older cultures in 20 years of maturing, but does have more money.
The title text mentions that Cueball originally had "regular" oil paintings. However, these appear to have been stolen from the Louvre , a famous art museum in Paris, which houses the Mona Lisa . Thus the "grumpy and unreasonable" detectives which came to retrieve the paintings. It even suggests that Cueball had attached those valuable and expensive oil paintings on his wall by poking through them with thumbtacks.  The fact that Cueball stole expensive paintings, poked them with thumbtacks, and did not realize that the detectives were trying to recover priceless artwork that rightfully belonged to the museum may demonstrate that Cueball indeed has not completely grown up.
The comic repeats a common theme of poking fun at how nerds tend to not fully "get" the culture surrounding them, adopting parts but remaining completely blind to other parts. Sharing and reading jokes about this may help people who experience that pattern handle the stress of being unable to completely conform, by bonding over the commonality.
[White Hat and Cueball are standing together and looking at eleven framed pictures on a wall.] Cueball: Getting older is so weird. 20 years ago, I thought thumbtacked Pokémon posters made my wall look so cool.
[Cueball has his hands raised up in a close-up.] Cueball: But these days I feel this compulsion to get framed oil paintings and spend hours carefully arranging them.
[Return to the setting in the first frame.] White Hat: These are all oil paintings of Pokémon. Cueball: Look, I’m meeting maturity halfway.
This is the only xkcd comic ever where the year when the comic was published, in the Gregorian calendar, is the same as the comic's number. This comic is numbered 2018 and was published on Wednesday, July 11, 2018.
