Energy sensations diminishing with time and practice. Movement killing energy sensation

First I would like to thank Alex Frantzis for his message in “Feeling chi”, 24 February 2011. It was informative and now I know that I have had at least some of these experiences.
1) My energetic experiences are mainly from Dragon & Tiger that I have practiced for about 2 years now. The first point here is that they tend not to increase but to decrease over time. So, during one of the first sessions a problematic point on my head started twitching and kept on for about 12 hours. Quite amazing. Also my head could feel the hand movements in No 6 and 7 very clearly. There were some other experiences too. They have not quite disappeared but are generally weaker now.
There is a viewpoint that energy experiences always diminish with practice as the organism gets used to energy movement. Would anybody like to comment on this?

2) Recently I participated in Paul Cavel’s weekend course of Heaven and Earth where he introduced a method of moving chi with your mind. It means basically focusing on a body part and then moving your concentration – along your arm or leg, or finger, or toe, etc. It really works – you get quite a clear feeling when you are quiet, sitting, standing or lying. Let me stress it is not visualisation: all you do is concentrate and then move your concentration. It always works. I have tried to integrate this feeling into D&T No 4 or into circling hands – so far without success. Physical movement seems to diminish or totally kill energy sensations, however softly I try to perform them. Of course it can be a passing problem but it would be interesting to know if other people have experienced something similar.
Would be glad for any comments from more experienced practitioners.

Avo