GB, MB, KB and other forms of digital storage amounts are the only forms of measurement that are consistent across the world, amirite?

Even these units can be confusing sometimes.

There are people who use K, M and G to refer to powers of 1024 (1 MB = 1024 KB, 1 GB = 1024 MB). However, in other cases, they are used to mean powers of 1000 (1 MB = 1000 KB, 1 GB = 1000 MB).

For example, hard disk manufacturers usually use the powers of 1000 variant when informing HD sizes. However, the disk size as reported by your computer is commonly shown using the powers of 1024 variant. So, your HD may say 500 GB in its label, but your computer may show a different, seemingly smaller number (465.66 GB).

To avoid confusion, there are people who reserve KB, MB, GB to refer exclusively to the variant involving powers of 1000, and use a separate set of names to refer to the variant involving powers of 1024: KiB, MiB, GiB, which stand for "kibibyte", "mebibyte" and "gibibyte".

Seconds, hours, any measurement of time