why do people only go to church on easter

The pagan ritual of families that live states apart getting together to celebrate the combination of the hope and happiness of winter solstice and the spring renewal of Easter-time.

Traditions include searching for christmas decoration, dying cut-out snow flakes, and hanging eggs on the branches of budding trees.

Typically celebrated in spring to avoid traveling in the harsh conditions of winter.
Why is it that some people only go the church on Easter, Mother's Day and Christmas?

My church was PACKED on Easter Sunday. With today, April 15, 2012, being the first Sunday after Easter, I couldn't help but notice that there were fewer cars in the parking lot.

A couple of other people I started talking and wondering why certain Sundays - Easter, Mother's Day, the Sunday directly before or after Christmas - are heavily populated but other Sundays aren't.

Where do people go? Why do they only go to church on those days?