Something similar pops up if you have to spend a lot of time looking at binary blobs with a hex editor. Certain common character sequences become familiar. This also leads to choosing magic numbers in data formats that decode to easily recognized ASCII strings. I'm sure if I worked with base64 I'd be choosing something that encoded nicely into particular strings for the same purpose.

Related trick I've learnt: binary data containing lots of 0x40 may be EBCDIC text, or binary data containing embedded EBCDIC strings – 0x40 is EBCDIC space character

Probably not a very useful trick outside of certain specific environments