Every year, thousands of Berkshire Hathaway Inc. shareholders trek to its annual meeting to listen to perhaps the world’s most storied investor, Warren Buffett. During this year’s meeting on Saturday, Buffett spoke at some length about his famous reluctance to invest in the technology sector and how it led him to miss out on investing in companies like Amazon and Google.

Buffett’s caution is understandable. Consider the publishing industry. Until a few years ago, the decline of traditional print publishers and the ascendance of e-books was a given. The numbers bore it out. But now they’re telling a different tale. The sale of e-books declined in the US and UK in 2016 while sales of physical books grew. Some of the same counter-intuitive return to the physical space can be seen in retail.

All of which goes to show that technology is not always linear. The rapidity of its evolution and the unpredictability of public attitudes mean it can take unforeseen tangents. Little wonder even the Oracle of Omaha is cautious.