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xkcd #3172: Fifteen Years
(imgs.xkcd.com)
Title text:
"Want to feel old?" "Yes."
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3172/
XKCD has a few of these tear jerkers that rank as some of my favorite all time strips
For all the popularity they have for their comedic and science strips, they also put out some really good emotional ones.