After I learned German for a few years, I lived in a region of Germany where many people spoke in a dialect. At the time I thought I had a pretty good handle on what was dialect and what wasn't. A good amount of dialect made it into my speech anyway, since that's how the locals spoke.

Later I discovered to my surprise that a few of the words I had placed in the "standard German" category were actually from the regional dialect.

I actually think it was more helpful to my language abilities to have learned two different German dialects (one of which was standard German). It also helped me to understand how languages change and what it must have been like several centuries ago when there wasn't a standardized German and people had to struggle to understand someone from far away area that in theory spoke the same language.

I imagine there is some blurring between what's an accent and what's a dialect, especially with your Scotland example. And to break it down further, as a native English speaker I can understand people in Edinburgh just fine, but Glaswegians are a mystery to me.

Your own native language probably has similar things - I know with Dutch, someone from one region can struggle to understand people from another region if they're speaking in their own dialect.

>understanding English as spoken in Scotland is a challenge.

Interesting tangent that I somewhat recently was made aware of; some of what they speak maybe isn't English.

https://en.wikipedia.org/wiki/Scots_language