I personally cannot relate to the 'loss of appreciation', as I haven't been living in EY for 12 years or even close. My longing to live and visit EY is very strong, and currently, I don't have much time to travel. But if someone asked me today, 'You have one place to choose, where would you want to go, I have no doubt about it that it would to EY. I haven't gone to EY many times, so I think I can safely say that my appreciation for EY is BH still there...
Your point is a great one, though it is really applicable to all areas of our Avodas Hashem, how often do we stop and take a moment to think about what we are doing before we put on our Tefillin? That first time as a 13 year old, with our New pair of Tefilin, we're so proud to do this mitzvah for the very first time, we do it with much excitement and vigor... But now, when we put on our (Talis) and Tefillin, do we really take even a small moment to think about what we are doing, before putting on out Tefillin, or is it CH'V just done by rote, as our daily routine? (Rhetorical question.) I gave Tefillin as an example, but from day to day, whenever we're doing mitzvos, do we have that excitement? That vigor? ...