The kabbalists teach that around the time of our birthday, things tend to happen that make us change, grow, or perhaps reevaluate our direction. This is because our birthday was our beginning, the seed for our life, the day that our soul chose to incarnate into this lifetime. Every time we return to this day, we are urged by the cosmos to make the corrections that will bring us closer to completing our spiritual job here in this world.
So when and if you experience challenges just before or just after your birthday, remember it is only the universe pushing you to grow towards your potential.