> Within myself I notice that the project becomes boring when there is nothing new left to be learned from it.
Yes, I have similar issue with motivation I have noticed, if I am presented with a problem to solve and I can see the solution before implementing anything, I am not really interested in coding the solution and testing it. I.e. the abstract or logical proof of the solution is sufficient for me (the fun part), but the actual coding, fixing some environmental problem and details of creating a working solution are (usually) much more boring - because they are almost always essentially the same.