What motivates you is a funny thing, it can be an idea or a word, maybe a simple concept or even a smell; Sounds corny I know, but finding motivation can be very important if you want to commit to something long term.
For my goals it's an ideal to try and be the best (not like better than others, just better than myself) which sounds weird because each time I improve the goal post changes, an impossible ideal but a worthy one, for what is as worthwhile as self-improvement? (it may sound a little selfish but you might be surprised how often self improvement also helps others)
I find is very hard to put anything in the "nope can't do it pile" but sometimes you need to take the time and decide what's important. But remember time marches on, each day the candle grows shorter, as much as we would like to think that we have all the time in the world mortality defines us as a species. For how we spend our days knowing that we have finite time is how our legacy will be judged.
We research days gone by... But forget we too will one day be history, Imagine how historians and scholars or a 21st century re-enactment group will perceive our time. Will we be remembered as Scholars? Warmonger's? Inventor's? or fade into mediocrity as we have wasted too much time on mindless games and achieved nothing.
Do a little day by day... by the end you will have moved mountains.
I am reminded of an old story,
An Old man has 3 sons,
He gave them gold coins in the amounts of 15, 10 and 5 gold coins
The first with 15 invested the gold, worked hard and returned 30 gold coins his father was pleased
The second with 10 gold coins did the same and returned 20 gold coins his father was also pleased
The third with 5 gold thought he was the wisest of them all and buried the coins to keep them safe, after some time he dug them up and returned them to his father. His father grew angry, "the gold was not to be simply kept safe, you were to use it and let to grow!"
The moral is simple, do not hide your gifts, use them and let them grow. To whom much is given much is required.