Miles grew up, and decided to transition - from "miles" to "kilometres".
That's it. You can laugh now.
=====SHILLING=====
Speaking of inherent artificiality and relativism of humour, and curious process of language drift in general as a tangent provoked by vague ruminations on the meaning of the word "humour"... Well, that's completely unrelated to the sentence above, but Snao's Patreon has only one level, last time I checked. One dollar per month. Not that large of a sum by any measure, methinks *wink-wink, nudge-nudge*...