I believe I have plunged enough and the drain is clear! I’m a bit hesitant to say that everything is better, because I bet there is a problem somewhere down in the depths of the plumbing, but the sink seems to drain fine now!

(I kept going in to try the plunger every 30 minutes or so and I would plunge it like 5 times (10 short bursts up and down and pull out fast the last time) and then let it sit for a bit, then come back and clean any junk out of the sink that might have settled, and fill the sink again with a few inches of water and start the plunging again).

Is there something I should/can do to help improve the “health” of my pipes on a regular basis?