Probably the reason you're noticing the time more than other times is because you noticed it once and realized it was your birth date. There may have been a moment of wondering if it meant something.

Because the wondering was never answered, your subconscious brings your conscious attention to the clock whenever it can at 8:18.

The seeing the same numbers over and over index page has links to more information.

Your life path number is an 8. Three of your four challenge numbers are 1 and three of your four pinnacle numbers are 8. Those numbers in your numerology profile might also predispose you to noticing the 8:18 time.