Future Self
Future Self
[Cueball is sitting at a laptop, reading code. The two separate parts of code as well as the two comments by Cueball is connected with "speak" lines, with the line from the code going down to the computer screen.]
# Dear Future Self, # # You're looking at this file because # the parse function finally broke. # # It's not fixable. You have to rewrite it. # Sincerely, Past Self
Cueball: Dear Past Self, it's kinda creepy how you do that.
# Also, it's probably at least # 2013. Did you ever take # that trip to Iceland?
Cueball: Stop judging me!
This comic is a joke about how the person you were in the past can be viewed as a distinct entity from who you are now, as well as the predictability of future events relating to your future actions.
The comic shows comments, informational notes left in the code that do not change the algorithm, from a project completed by Cueball some time ago that is still being used and maintained.  It is implied that Cueball is looking at these comments because the algorithm, a parsing function, is no longer working. These comments were written by Cueball's "younger self" in anticipation of being read by his "older self" at a date close to the present. The function has held up to the younger Cueball's expectations as it has lasted until the publication date of this comic, September 2014. The comments indicate a firm belief that the parsing function could not be easily "re-kludged" to handle the new situation but instead would need to be re-written.
These comments are surprisingly accurate, leading Cueball to rhetorically reply to his younger self that these comments were creepy. Cueball's "younger self" must have anticipated a snarky reply and reminded his older self that his older self has likely not fulfilled his dream of going to Iceland. Cueball again replies that his younger self should stop judging him.
In the title text, current-day Cueball lashes out at his younger self, further emphasizing the way he is viewing his past self as a different person, blaming the ineffectiveness of his past self's coding for never going to Iceland.
A comment is a line, or a portion of a line, of code which should not be executed. A number of computer languages, including Python , use "#" to indicate "the remainder of this line is a comment". The comment symbol tells the compiler to skip to the next line, ignoring everything after the symbol. Programmers make use of comments to leave notes about what a particular line or section of code is meant to do, places that require debugging, ideas for future revisions, etc.
The language in the comments is similar to how people address themselves in personal time capsules , in which they put letters away to read years later to see how much they've changed.
A " parse function " is code that interprets some form of input and makes sense of it in a way that enables functionality in some other part of the code. Parsers are commonly used to extract useful information from a source external to the algorithm. 
Often parsing functions are written using regular expressions or in some other write-only language style. Parsing can be a difficult problem to solve, and programmers will often take shortcuts (perform kludges ) based on assumptions on the kinds of input that the parsing function will have to handle, or possibly code through means of trial-and-error.
As the programmer may not have control over the input, such as reading a page from someone else's web-site or using the output of an unpredictable program, an input that does not match the assumed input syntax in can cause the parser to break, even if the parsing function has not changed.
[Cueball is sitting at a laptop, reading code. The two separate parts of code as well as the two comments by Cueball is connected with "speak" lines, with the line from the code going down to the computer screen.]
# Dear Future Self, # # You're looking at this file because # the parse function finally broke. # # It's not fixable. You have to rewrite it. # Sincerely, Past Self
Cueball: Dear Past Self, it's kinda creepy how you do that.
# Also, it's probably at least # 2013. Did you ever take # that trip to Iceland?
Cueball: Stop judging me!