Meaning of Christmas

I don't understand how people find the meaning of Christmas. To start with, it is the birth of Christ... but he told us to celebrate his death, not his birthday. In this part of the year, you notice that people are more caring, happy, helping homeless, giving food to people and even collecting more money for good reasons as I always see in Walmart for the Salvation Army. At the first glance, it look pretty good and nice. The problems is, why people need to wait for this occasion to do these? I believe it will have more meaning if is it done throughout the year and not trying to compensate that lack or void in the heart just for a month and a half. Just keep thinking about it is crazy, but true before my eyes. I was reading about a truce made between a British soldier and a Russian soldier during WWI. These countries agreed to have peace and celebrate Christmas together. Everybody was celebrating, eating and playing like there was nothing to worry about. The British one told the other soldier: "tonight we are celebrating, but tomorrow you will fight for your country and I will fight for mine". What is it then the real meaning of Christmas? Certainly is not about gifts and celebration... it should be a spiritual change and the quest to be a better human being.