Goal muscles vs task muscles
You probably have developed your “task muscles”, just like a lot of us. Meaning that we are good at crossing off tasks and keeping focussed on finishing those.
An interesting way to look at “doing goals” is to think in terms of “goal muscles”: just like with muscles in our bodies, repetition builds your strength and ability to finish goals. With physical training you start small, and only by sticking to a strict training schedule you get to a point where you can take on the big weights. If you start with goals that are too big, you’ll fail and with that there is a big change you’ll lose motivation.
Start small and remember that there is no such thing as “I’m bad with goals”. You only have to train a little more.