I use a simple method of keeping track of ideas and goals: Now, Later and Eventually.
There are certain things that can, or should, be done in the very short term. An idea for a birthday present. A quick process fix that can be done without much effort. Something you want to do this this week or so.
"Later" is something that doesn't make your immediate list, but is still relatively short term. You don't want your thinking to digress at this moment, but the idea is good and should be pursued soon. Later goals fall into the category of "the next time this comes up, I'll address it."
"Eventually" goals and ideas are things that really are good ideas, but the timing isn't right to pursue them now. You don't want to lose them, or spend time on them now, so you can keep a list of longer term items to revisit occasionally to see if any have moved into the "later" time frame.
This simple triage method may help you keep on track to accomplish what you can do now without distraction, but still allow you to prioritize and manage those good ideas that will make a difference in the future.
-- beth triplett