Well, y'all, we made it through 2020. I know it doesn't mean anything, really, but I always like to think of the new year as a new start, whether it's setting intentions for yourself or continuing your goals from last year with a renewed energy.
I started NaNoWriMo last year with the intention of finishing my book. However, I was also working a full time job and editing for clients, so deadlines for my clients took priority over finishing my own projects. I took the last few months of the year to focus on myself and prepare for this new year with a new outlook on life and what I want, and I feel like I achieved that for the most part. But in doing that, my goal of finishing my book in November was pushed to the end of last year, and now I'm shooting for January.
That's the beautiful thing about goals to me: they adapt. They don't stay the same, and that's okay. If you start off with wanting to write 1,000 words a day and you can't after you've tried for a week, dial it back to 500. Is that more attainable? Just because there's a "magic internet number" of 1,000 words, that doesn't mean it's feasible for you, especially if you're not just writing all day. Every day is different - there's the potential for new inspiration as well as new challenges.
If you create a goal and don't stick to it, don't feel bad. You probably have a very good and valid reason you didn't meet your goal for that day. Try again tomorrow, and try to keep your head up.
Also an important piece of creating and keeping goals, especially with creative work like we do, is not to force creativity if that's not something you're good at. For me personally, if I force myself to write when I'm not feeling inspired or creative in any way, I'll have to take more time in revisions trying to figure out what my intentions were and fixing it so that it's decent, that I may as well have just waited for the spark of creativity to hit before it started. Now that's not to say that you should go days and days waiting if you have a goal in mind - but try to work on something else for a while if you can: perfect your outline, work on character sheets, draw something pertaining to your book, do some worldbuilding that isn't necessarily key to the plot, but might be interesting to think about.
But don't give up if you have a lapse in success. It doesn't have to be perfect; it just has to get done.
There's always room for improvement if you look hard enough, so it's very unproductive to dwell on it. Do your best!