Copy-paste is the sliced bread of software engineering. Think this over for a second.
Nothing has done as much good for software engineering as the ability to copy and paste text. No tutorial or fancy wizard. No object-oriented programming with its thousands of man years of research and development. No agile, waterfall, or agile waterfall development cycle. No drag-and-drop GUI software development tools or any other thingamajig created in the last 20 years.
None of them can beat click, drag your mouse across the text you want to copy, click copy, click where you want to paste it and paste. I guess that makes ASCII character string the most universal data structure ever and copy-paste the most fundamental operation in all of software engineering. But more importantly, copy-paste demonstrates that simple things can have profound and lasting impact.