Solar eclipses occur about twice a year. but seeing a total solar eclipse is often described as a "once in a lifetime" experience. why is it so rare to experience a total solar eclipse?
total solar eclipses only occur once or twice a century
. the width of the moon's shadow is very narrow, so a particular area is very unlikely to lie along the path of totality during the eclipse.
total solar eclipses usually occur in late winter, when clouds are most likely to block the view.
if you aren't paying attention at the time, its very easy not to notice a total solar eclipse.