I just stumbled across the following in Wikipedia:
The Baader-Meinhof phenomenon occurs when a person, after having learned some (usually obscure) fact, word, phrase, or other item for the first time, encounters that item again, perhaps several times, shortly after having learned it. This is a specialised version of the effect of serendipity.
I’ve been searching for the name of that phenomenon for years now. In fact, if you’ve known me for any time at all, I’ve probably asked you if you knew. I cannot effectively describe the sense of completion I am feeling right now.
Now that I’ve finally discovered the name for this phenomenon, I totally expect to hear it again in the next few days. In fact, I totally expect someone who reads this to comment that he or she just learned about this in the past few days.