I don't know anything about computers. I don't even know how often to change the oil.

The line is a self-deprecating joke built on a category mistake: the speaker claims ignorance about computers, then “proves” it with an even more irrelevant admission about car maintenance. The humor comes from conflating two kinds of technical competence—digital literacy and mechanical know-how—suggesting a broader feeling of being out of one’s depth with modern technology in general. As a quotation, it functions as a comic disclaimer: it lowers expectations, invites camaraderie from similarly baffled listeners, and lightly satirizes the pressure to be competent across rapidly changing technical domains.