fiction(al), science

You can't build a car that violates the laws of physics.  Same goes for a time machine.  You can't go just anywhere, only to places it will let you go.  You can only go to places that you will let yourself go.

I don't miss him anymore.  Most of the time, anyway.  I want to.  I wish I could but unfortunately, it's true: time does heal.  It will do so whether you like it or not, and there's nothing anyone can do about it.  If you're not careful, time will take away everything that ever hurt you, everything you have ever lost, and replace it with knowledge.  Time is a machine: it will convert your pain into experience.  Raw data will be compiled, will be translated into a more comprehensible language.  The individual events of your life will be transmuted into another substance called memory and in the mechanism something will be lost and you will never be able to reverse it, you will never again have the original moment back in its uncategorized, preprocessed state.  It will force you to move on and you will not have a choice in the matter. 

Everyone has a time machine.  Everyone is a time machine.  It's just that most people's machines are broken.  The strangest and hardest kind of time travel is the unaided kind.  People get stuck, people get looped.  People get trapped.  But we are all time machines.  We are all perfectly engineered time machines, technologically equipped to allow the inside user, the traveler riding inside each of us, to experience time travel, and loss, and understanding.  We are universal time machines manufactured to the most exacting specifications possible.  Every single one of us.