If you know more than 365 people, it is statistically likely that one of them has their birthday today. Then you will congratulate him or her - on the birthday. Strange. Congratulations are usually given for something that someone has successfully achieved. On their own birthday, however, no one has ever been able to contribute anything to it. Nevertheless, we congratulate... what for? Perhaps this can be an occasion to congratulate a birthday person next time for having behaved in such and such a way in this or that thing or situation that he or she has become the person he or she is - in other words, to express appreciation for a quality or achievement that this person has accomplished in a very concrete way. Let's see what that triggers on the birthday then....
I wish you an extraordinary day!