Dilution of work

At times one becomes frustrated on the lack of progress with particular project - why havn't I been able to finish this yet it isn't too hard? The answer I'm thinking at the moment which is more than applicable to me is one of dilution to take a chemistry adage (probably part in due to all the PCB's I've recently been etching). When a chemical (take Ammonium Persulphate for example - my current etchant of choice) is diluted it will still etch boards - just a whole lot slower. This seems apparent to how projects are coming along - between lecturering, supervising, researching, consulting and leading 2 study groups the time spent on projects seems somewhat diluted.
Realistically if I had one week completely free of distractions I could probably finish all the code for the submarine and have it running the the water for some testing - but when is that week going to come - not soon it would seem.