The author laments that his habit of typing “alt-tab” (to switch to his web browser) and then immediately entering a url of a popular news site to quickly check on the state of current news affairs is so ingrained that he does it reflexively. He even does it when using a typewriter, which cannot browse the internet. This leaves tabs and urls interspersed all throughout a heartfelt hand-typed letter to the author’s grandmother. This is especially funny because it is unlikely grandma will understand what is going on, because she is old and the internet probably confuses her.
