Your hardware doesn't care for you, like you might care for it.
Hardware is fickle, temperamental, unpredictable, and moody; disks, the rebellious teenager of the hardware family, take this to the next level.
You will find yourself confused at some point in your career, baffled as to why seemingly unrelated errors are occurring in disparate parts of your system. Your SSH daemon might be randomly dying at odd points in a transfer, NTP might be drifting, your database might be locking up, and all the while you're tearing your hair out trying to find the cause.
Hardware is usually the answer to these random issues (when it's not time, as we discussed previously). A bad stick of memory can fail in weird and wonderful ways, while a disk occasionally going read-only can mean sporadic and nighttime-disrupting events that can be tempting to resolve with a particularly...