IDK, but probably thanks to a lot of trauma (TL;DR: ableist bullying), I try my best to extend projects or just leave them unfinished. Sometimes I just start new ones for no other reason that I don't have to finish the previous ones on time.

Sounds more like ADHD territory to me

What do you feel or think when you are approaching the end of the project? Are you seemingly unable to force yourself to finish or are you actively choosing to delay?

Is the "on time" part the critical piece? Could it be persistent demand for autonomy? Aka Pathological Demand Avoidance?

You might just be looking for affirmation about being autistic, so this next part might not be useful. If you are trying to solve the problem or at least learn more about it so you can see what you can change and what you need to accept, it would be helpful to know why you do this.

For example, possible reasons to not finish a project:

• novelty wore off
• fear of imperfection
• issues with transitioning to the next task
• executives dysfunctioning
• reacting to set deadlines or other stipulations to exercise autonomy

Some of those slot more neatly into autism or ADHD but it doesn't mean it's one or the other!

Are you afraid of the judgment you might receive upon completion?

It may also be a comfort thing. The end of a project means the end of a status quo you have come to expect. Change can be scary because we don't know whether the next thing will be worse.

I'm no expert, just guessing.

I think lot's of people here provide good input but clearly no one can answer that for you even if you had provided more detail. If this is a concern for you and not just a curiosity then it is worth while to sit with this question and live, in your mind, through the experience on what it means to finish a project.

If its not, i definitely also independently struggle with that

For me its the perfectionism and false sense of finalitity that gets me - i (attempt) to counter those thoughts with:

• "Its never permenant: actually i can just change it if i dont like it after i say im done"
  • additionally "i am not a liar if i say its done and then update it later; no one actually thinks this"
• "i dont even like perfect super polished things, i like the charm on literally everyone elses creations, i ought not be a hypocrit to just myself"

And then i ship it - and let go - and its almost always good enough if not really well done and then it quickly fades into the past as the next project captures my hyperfocus (for better and worse lol)

I experience this with video games, I get most of the way through them and then just leave them there, but I don't know that in my case that it's an autistic thing. I guess I experience something somewhat similar though as another autistic person, so there's that?

When you're engaged in a project, your brain is producing dopamine and you are happy. If the project ends, you'll go back to the nether space where you need to find the next project. We hates that space.