Seeing 12:34, Not Coincidental

You are correct, it is unlikely to be coincidental. What is happening, most likely, is that when you see 12:34 you recognize it as the number you remember seeing. That recognition makes it almost certain that you will remember seeing the number.

Imagine that a person sees a hundred numbers during the course of a day. Some numbers are seen repeatedly and some only once. The person sees the numbers in the order they appear in their environment, not exactly random but also not any predetermined order. Just a bunch of numbers the person is exposed to during the course of their day.

Rarely does the person remember seeing those numbers.

Sometimes, however, a certain number is remembered as being seen. The digits of the number may be arranged unlike most other numbers according to the person's experience and opinion (12:34 and 11:11 can be examples). Or, the number may represent something special to the person or have an emotional significance, like their birthday number or the day they got engaged.

Because the number is not quite ordinary, it is more likely to be mindfully noticed and remembered.

When a person remembers seeing a number — the same number repeatedly for a period of time — it seems like that is the only number they see. But it's the only number they remember seeing, not the only number they have seen.

After a period of time when the same number is recognized as being seen, an emotional investment occurs in the sense of wondering if it means something special or personal.

At that point, there is sufficient emotional significance to virtually ensure the person will notice and remember that number every time it is available to be seen in their environment.

For more information about that, see the Why You Start Seeing Certain Numbers Again and Again article. And also Why People See Certain Numbers All the Time.

As explained in those articles, it is likely the reason you are seeing 12:34 so often.