The personal computer unfortunately has lost one of the most basic and useful features of the earliest computers. Let's say you're surfing the web. You find something and want to copy both the web address and a few lines for a friend, but you can copy only one thing at a time without opening up your clipboard. So you copy the web address (from which you can always get back to the page). Meanwhile you spot another interesting link to something else for a different friend. But now if you copy even just the web address it will overwrite the other web address. So maybe you open another page on your clipboard and get distracted or maybe you just forget and overwrite your first address and by the time you realize it you can never find it.
Or maybe you copy something you'd like to keep for a while to share with everyone you write to. But if in the meantime you use copy and paste for something else, it's gone.
It wouldn't have to be like that. From the beginning one of the most fundamental computer operations, y = x, put whatever was in the x register in the y register. A register was like a clipboard, only you had as many as you wanted, and you could call them x1, x2, ..., or whatever you wanted. COPY just means "Clipboard" = "Whatever is Highlighted." PASTE means "Next on screen" = "Clipboard." Our laptops (and desktop personal computers) should have lots of clipboards and lots of COPYs, maybe Copy1, Copy2, Copy3, ... . The first interesting thing you Copy1. The next Copy2. The next Copy3. Your laptop would remember them all separately. Then later you can Paste1 or Paste2 or Paste3. There would even be a special command PasteAll that would put them all on the screen open in front of you.
If you'd just been to say bridge nationals, you could write a few pertinent sentences, Copy9, and paste them into lots of correspondence with Paste9. Or if you're working on something that uses a certain special symbol a lot, you could Copy8 it, and then just Paste8 it whenever you need it.
Incidentally this feature is available as aliases in my beloved mail application Eudora, which unfortunately doesn't run under the latest Mac operating system.
A laptop's long-term memory is huge, and it never forgets as long as it lives. But a laptop's short-term memory, in the form of copy-paste, can remember only one thing at a time. That's got to change.