“Remember how you learned the words 文字 and 通り? Well an “avenue” made of “letters” is [literally] [to the letter]. Wink.”
I feel like I’m missing something here. How are we getting “literally” or “to the letter” from an “avenue made of letters?” I’m fine with wordplay stuff but I’m completely lost on this one.
In Latin, litera/littera meant “letter” – this is how we got “Literature” 
It doesn’t really need to make sense as long as you can mentally connect the mnemonic (any mnemonic) with the WK ‘meaning’.
That also goes for the mnemonics that I make up for myself (some of which are not suitable for discussion in polite company - but as long as it does the trick it’s GTG)…
(As a PG-rated example, for the kanji 矢 my personal mnemonic is ‘yah, that’s an arrow’. No, it doesn’t make a lot of sense, but it works for me.)
The ending “~通り” in Japanese usually means “according to…”. So 文字通り can mean “according to the letter(s)”.
Other examples of “~通り”:
Dang, I was thinking about that but I missed that “according to the letters” is the same as “to the letter.” Anyhow thanks for clearing that up!
(As a PG-rated example, for the kanji 矢 my personal mnemonic is ‘yah, that’s an arrow’. No, it doesn’t make a lot of sense, but it works for me.)
lol I do that too - my mnemonic for 有 was just “[you] have ____”. Honestly idk if it’s even a mnemonic at that point but it worked so
Ha!
That’s exactly the mnemonic that I use for 有 
Love this, I’m going to put it into my own personal pneumonic on wani.
This really inflates my ego!
I literally couldn’t make one for you if I tried.
If it helps, another common example is 「その通り(だね)*」-- something you’ll hear a lot in Japanese conversation, both in real life and in media, as one person concurs, agreeing exactly with what another just said. Cheers! 
*I think it also helps that there’s no rendaku here, so it’s pronounced 「そのとおり」-- you don’t have to remember to transform it to 「〜どおり」!
That even works with Mandarin, albeit only as a pinyin mnemonic and not as a pronunciation mnemonic.
I confused just now that pneumatic devices aren’t pneumonic, and also aren’t mnemonic devices.
