Acts should be symbolic to convey the truth that they represent. Birthday is not just celebrating the years we have left behind us but looking forward to the years to come. Blowing off a candle or lamp has always symbolised the sniffing off of life, the number of years that have been snatched away. Lighting a candle on the other hand always symbolises the birth of new hope, new life, of renewed aspiration. Keeping all the candles lit up is like the joining of aspiration of the years to strengthen the aspiration of the present so that we may move forward towards the future with a yet greater intensity and impetus. In India even as late as a few decades back (even my childhood) before the Western influence and symbols caught up, birthday was always celebrated by lighting a lamp (diya) before the Deity and prayers for the well-being. Now it is blowing off the candles and throwing off a party.
Affectionately,
Alok Da