Apple's Time Machine works in a funky way, so go over to your local store and get a large 4TB (or bigger) drive. Also, get Shirt Pocket's SuperDuper program, which will make a bootable external disk that replicates the internal drive in your system. In case something goes wrong with your internal drive, reboot your Mac while holding down the "option" key, and boot the backup. The newest version 3.2.5 supports Mojave and includes their Smart Delete, Smart Wake, and Smart Update features.
Mike has a printer that he needs to have repaired, but he's worried that the printer memory could get hacked. Leo says that it's definitely possible. But Leo doesn't think it's really a cause of concern. At best, it'll only remember the last job it had. So it's not really that big of an issue, just a theoretical concern. Just because the memory is there, doesn't mean it can be accessed or that it will even stay there once it's unplugged.
Our memory may be negatively impacted by the instant access of information online. The authors pose one simple example: Ask yourself how many countries have flags with only one color. Regardless of the answer, was your first thought about flags? Or were you thinking about where you could find the answer? In the old days, you may have thought about all of the flags that exist and which ones have one color. Now, you may be thinking about your Google search term. This is called "transactive memory" and it's been going on long before the internet.
Gil wants to breath new life into his old Dell 2.8 Ghz P4. Leo says that's pretty old and it's not really worth putting a lot of money into. Gil could beef up the memory to 4GB. That would help a little. Go to Kingston.com or Crucial.com and use their memory tool to find the right memory. At that age, it's probably better to apply that money to a new computer.