Be mindful but of what?

It is supposed to enhance the value of my life to be mindful, which usually means staying alert to, and focusing on, what is actually happening to me, not to go off into la-la-land too often or unconsciously.  I wrote about my awareness on the bus ride through France that using that time to get my accounts in order while skipping the scenery I had journeyed to see would not make sense.  It would be a waste of a good opportunity to see what I normally don't get a chance to see.  Buddhists and others are always urging us to be mindful of our lives and bodies, of our experiences as we have them.  They advise avoiding what Thoreau wanted to avoid, which was arriving at the end of life only to find that he hadn't lived. 

But as anyone today with several children, with several possible area and regional trips, with several restaurants serving wonderful daily specials, with several channels showing great shows, several libraries with books and magazines not to be missed, with sales of audiobooks at unheard-of prices, dozens of web sites that are each capable of blowing one's mind, as people today can tell you, you can't be mindful of it all.  There is simply too much world, too many ideas, too many opportunities.  We don't have time or attention enough to be mindful of them all.

Whichever way I turn, I miss things behind me.  Whatever I choose omits far more choices than I chose.  I have paid attention to some things but I have no way of knowing if my choices were really the best.  I don't want to waste time and effort on worrying about or regretting the many choices I refused, not to mention the oceans of things I could have chosen but didn't even know about.  This being mortal and time-bound is a tough struggle.