...are like ships.
If you know them, really know them, you'll know what's coming long before it hits you. I've never lost data to a hardware failure. I've had hardware failures, just never lost data to one. (Well, important data, anyways. I lose -that- by reformatting and forgetting a folder. And even then I usually have backups. Somewhere around here I have a floppy disc with all the MIDI compositions I created as a teenager. I don't have a floppy drive anymore, though.)
Blue screens of death usually mean a component is going out, provided you haven't recently updated drivers or something like that. Black screens of death (sometimes they're blue...) complaining about corrupted virtual disks guarantee your hard drive is dying or dead.
You get to know the creaking of the timbers, so to speak. When the computer should run slow - when it shouldn't. What actions are likely to cause the whole thing to lock up.
What weird noises are normal. What weird noises are not.
RIP, my old work laptop. You served me fairly well. I can hear your fans breathing their last death rattles, I can feel the heat off your motherboard on my knees. Your keyboard no longer faithfully writes e's, a's, i's, d's, r's, and a dozen other letters until it has warmed up, warning me that some of your circuitry is cracked and brittle. You don't lock when closed anymore, and your monitor tries to open from all four sides. And your "new" hard drive isn't spinning up to full speed anymore, and I can hear the clicks of head crash near-misses.
So into a quiet retirement you go.