Hi masterKamera - I think we all have things that get in the way of progress.
Work can leave you tired and not having enough time or mojo to do a little bit here and there throughout the week (I find this especially so for me as I tend to work long days... which means I tend to be most productive at the bench on weekends, even if only for a couple of hours here and there). Other times, for me, it can simply be the long road ahead on a project in its early stages that can slow the urge down. I find once I get past the 'tipping point' on a build, be it something like completion of the cockpit, or priming, or decals, I am off and away again.
Otherwise, what tends to get me motivated again seeing the great builds of other modelers. It reminds me that I still have a long way to go with my skills, and the only way to do that is to get off my backside and get to the bench...!
Even so, my build rate stays particularly slow. Where as in past years I could get through 10+ kits a year, these days I am down to 2-4 builds a year, in a good year (I am up to 3 so far this year, and I suspect that will be it, given the builds I have on the bench right now are not simple).
Cheers,
BC