This is basically a note to myself or another interested person to find a good question that may serve as a canonical question-answer pair for the above issue. It was just asked yet again, which might be the thousandth time I've seen it asked. ;)
2 Answers
Why is my transaction not getting confirmed and what can I do about it?
Probably has the most canonically worded question title, although this is another good option.
I think a good answer could reference either/both of the below question as well:
I also just found
What happens if my transaction is not accepted because I did not pay fees?
of which I like the answer for being a bit more elaborate. No time right now, to further explore though.