xkcd #2942: Fluid Speech
Alt text:
Thank you to linguist Gretchen McCulloch for teaching me about phonetic assimilation, and for teaching me that if you stand around in public reading texts from a linguist and murmuring example phrases to yourself, people will eventually ask if you're okay.
That's a different issue from sandhi. Vocabulary and dialect are another area of active study (often paired with yet another realm: sociolinguistics: the language you speak changes according to your social environment) that is a real rabbit hole.