is it best just to let these things slide?
Possibly. It's certainly a reasonable thing to do. Also, if you have many citations of that paper, I'd definitely say let this slide.
The reference wording doesn't make any sense though. The only connection is the concept of an attractor network.
So, the references makes a bit of sense, but the wording doesn't. Unless that paper makes an invalid claim regarding the contents of your paper, that's not so bad. Certainly it doesn't reflect poorly on you.
I would call nonsense.
You're being much too harsh. Maybe the author typed in the wrong citation? Maybe they meant to reword the text near the citation and forgot to do it when submitting the final version? etc. Give people the benefit of the doubt.
If this really bugs you, email the authors of the citing paper, tell them you noticed the citation, and ask them if they could explain briefly in what context they used your results (i.e. not giving them your impression beforehand). If they don't respond - let it go. If they do explain, and get it wrong, then you can write back saying "Oh, but you wrote that XYZ while in fact my paper is ABC"; note you are not judging their abilities/skills/intelligence, just politely pointing out a discrepancy. If they at all care, this is the point they might consider a revision and/or an erratum, and/or a change in future uses of the same text/ideas (e.g. journal version of conference paper, placement in thesis or book chapter).
It's still quite likely that they'll tell you "Oh, well, maybe you're right, but what's done is done". You'll have to live with that, I'm afraid.