I was on the way to work and happened to hear "A Thousand Miles" by Vanessa Carlton. At least I think that is what the song is called.
As I listen it occurred to me that what she is saying is not humanly possible. There is no way you could leave the same day, walk a thousand miles, and finish the thousand mile journey by evening. It is just not physically possible. At a very fast walking pace of 5 miles per hour it is going to take you 200 hours to go 1000 miles. Even if you could run and get it up to 20 miles per hour that is still 50 hours. It is not humanly possible to keep a pace of 5 miles per hour for 200 hours, nor 20 for 50.
Even in a car a thousand miles is pretty much an all day journey.
So let's say you did attempt the 1000 mile journey at top speed of walking 5 miles per hour. Let's just envision how appealing you are going to be to this person who you are obsessed with. You are going to be sweaty and exhausted. You are going to be blistered on your feet from walking and on your face from being in the elements (sun, wind, rain, and so forth). You are going to be covered in your own waste, since in order to get there as fast as you can and not dip below the five mile per hour rate you will not have opportunity to stop and take care of personal needs. You are going to be hunched over from carrying a water pack containing the ten gallons of water you are going to need to sustain yourself and prevent dehydration. As well as several pounds of food. Again you will have to carry it, because there is no time to stop and get a drink or a meal on the way.
In addition to the physical wreck you will be, you will also be emotionally and mentally destroyed. We will set aside the fact that to be so obsessed to begin this journey in the first place you were likely already a fairly unstable person from the start. The exposure to the elements, the physical pain, and the seemingly never ending stretch of road will crush your spirit and you mind will start to check out.
While on the surface this is a sweet display that someone would express that they would do anything for someone they love, but this level of obsession is not healthy to the person or the relationship. Not only is it unhealthy, but it is dishonest. Clearly you are not going to walk a thousand miles in a day and you are lying to them and yourself if you say that you will.
How about this instead? I will be with you for better and worse, in sickness and in health, for time and all eternity.