Yes, I do know this, but I have trouble living it. I'm like that in many regards. I can't seem to clean a little here and there, I have to clean my entire house. I just have a bad habit of being very perfectionistic, and needing to do things to my full satisfaction or I tend to not to them at all. Like meditating. I know I can just sit anywhere, but I enjoy doing the whole thing, candles, incense, lighting, etc. I do realize it's a flaw, believe me. I'm not meditating at all right now, which I know is not a good thing. I'm not defending it, just describing it. I just feel so distracted lately, I'm not sure why. For a good 2 or 3 hours today I listened to some CD's on Lojong practice, took extensive notes and studied them. Although I am glad I accomplished this, it did occur to me later that I could have meditated with some of that time instead of studying. Maybe I need to set a time every day to meditate and not wait until I feel like it. I'm obviously meditation lazy, that's not a good thing! I'm also suspecting that I should perhaps not wait until I'm in the "right frame of mind" to meditate. I imagine that even sitting in the wrong frame of mind, if there is such a thing in meditation, will at least give me the benefit of making it routine, and maybe the "right frame of mind" will eventually return.
What I find most meritorious is that you are striving and interested about improving your practice. We all had that kind of problems, more or less similar to yours.
Don't get overly upset about it. It's just a small difficulty that you will overcome, so try not making it a giant problem. Don't force yourself too much or you'll feel "mentally tight". If needed, simply take a break from formal meditation until the will to do it comes back. Relax and do little informal sessions during the day without thinking: "now I'll meditate". Just pause a little and do it for a little while. However, if this "resistance" prolongs itself for a long time, you'll need to put some effort into it. Sometimes we need to make sacrifices and just sitting while having lousy sessions (in terms of goal, but good sessions in the end). But that may not me your case and some time off sprinkled with little sessions may be what you need.
It is also a good idea to contemplate a little the four thoughts that turn the mind to the Dharma.
You can read about them here: http://www.berzinarchives.com/web/en/archives/sutra/level2_lamrim/overview/general/4_thoughts_turn_mind_dharma.html
It would be very good if you could talk to a good teacher about this. I'm giving you suggestions, but I am not qualified to help you as a teacher, so I may get it all wrong; I'm only a buddy with a little experience who too dealt with this sort of problems and means well. This goes without saying, but I said it anyway, just to be on the safe side and avoid misleading you. If you want solid advice, ask Namdrol. (I think one day he will forbid me from sending him people with questions, but until then...)