I think this quote attributed to George Eliot is just terrific:
"It is never too late to be what you might have been."
The quote is framed, along with a picture of a Mary Engelbright character, in my mother-in-law's bathroom. I become very contemplative everytime I visit the bathroom and I read the quote. It reminds that if I become dissatisfied with some aspect of my life and I want to make a change, now is the time to do it.