The bubble of population growth ie the "boom" in "boomer" is part of what contributed to their wealth. The surplus labor of boomers in their youth did not need to support as significant a population of older generations who were less numerous to start off with and additionally lost a great many as casualties of war. As boomers age the reverse becomes true and the new generations must support an enormous elderly population of boomers. This intersects with the many other factors that we are all familiar with on this forum.