Explanation
Correct answer: B.
Choice B is the best answer. The speaker says that they wish they could remember when they first met someone, but they can’t remember the meeting at all, because they didn’t know at the time that the relationship would "blossom" later on.
Why the other choices are wrong
Choice A
Choice A is incorrect. The speaker does say that the relationship has "blossomed" over time, but only briefly at the end—and they don’t really "celebrate" that fact. Rather, the text has a more regretful tone: it’s about how the speaker can’t remember first meeting this person, and they wish they could.
Choice C
Choice C is incorrect. The speaker doesn’t mention an anniversary—in fact, the speaker can’t remember when they met the person they’re talking about.
Choice D
Choice D is incorrect. The speaker doesn’t say that they neglected the relationship. In fact, the speaker suggests that the relationship has become very important to them—that’s why the speaker wishes that they could remember their first meeting.