Javier Marías said this quote
“ The day we didn't spend together, we will never spend together, what someone was going to say to us on the phone when they called and we didn't answer will never be said, at least not exactly the same thing said in exactly the same spirit; and everything will be slightly different or even completely different because of the lack of courage which dissuades us from talking to you.....none of that will ever be repeated and consequently a time will come when having been together will be the same as not having been together, and having picked up the phone the same as not having done so, and having dared to speak to you the same as if we'd remained silent ”