Tying and Untying

A few years ago, I led an amazing trip to Israel with the members of my Eim Habanim Semeichah shiur. During the trip, we stopped at the P'til Techelet factory, where I picked up two pairs of techelet tzitzit - one for my weekday tallit, the other for my Shabbat tallit. I intended to attach them as soon as I returned, but never did. I'm pretty sure that there are some deeper psychological reasons for my not having "switched over." Or maybe I was just being lazy.
Finally, this past Friday I started the job. I went to a minyan that I thought started at 8am, but turned out to begin only at 8:30am. I had a half-hour to kill, so I started on the tzitzit.
Obviously, before I could put on new tzitzit, I had to remove the old ones. So I began to untie them, which actually took quite a long time. At one point, someone came up to me and said, "You know, you can just cut them off. That's what most people do."
I didn't mention the obvious: I didn't have any scissors with me. But there was something deeper. "Yeah - but then I can't use the old strings again if I cut them. This way, I still have usable tzitzit."
I'm not sure what it was, but there was something about the act of untying that I found particularly satisfying. It also gave me an interesting insight into the laws of Shabbat.
The Torah prohibits us from performing inherently constructive acts on Shabbat. According to many opinions, the rabbis derive the thirty-nine melachot (prohibited activities) from the construction and service in the mishkan. Among those thirty-nine are the activities of tying a knot, and untying that same knot. (I gave a shuir on the melachah of tying in my Hands-On Halachah:Hilchot Shabbat series. You can download the audio here, and the source sheets here.) While we can readily understand the constructive nature of tying, how is untying constructive? Aren't you undoing a knot - an act that's inherently destructive?
The answer, I think, is that while you might be untying the current knot, you're really preparing your rope for a new knot. In this way, untying is actually the very first act in the tying of the next knot. Because, if you really didn't need the rope anymore, instead of untying the knot, you'd simply cut the rope, rendering it useless in the future. Interestingly, cutting string or rope is certainly not prohibited from the Torah, and in some instances is actually permitted on Shabbat. (Check with your LOR - local Orthodox rabbi - for details.)
This got me thinking about the knots that we make in life - and what we do with them when we no longer need them.
Life is a process of relationships. Sometimes we use a knot for a period, but then need to move on, whether it's to a new job, a new friend, a new social group. What do we do with the old knots? It's always easiest to cut the string. It's instantaneous and painless. But then you don't have the string available, should you need it in the future.
On the other hand, untying is hard work. It takes time, and can leave our fingers blistered and frayed. (The tighter the knot was, the more difficult it can be to untie.) But that effort and energy exerted to untie the knot is a constructive act. You may no longer want the friendship - but the relationship can end on a positive note; the job may not have paid well enough, but instead of firing off a "go to hell" email, maintaining positive contacts could prove useful in the long run.
But those contacts take energy, both mental and even physical. It's the energy of untying a knot, carefully and slowly, so that the strings are still there to tie the next not should the need arise.