I understimate always how long tasks takes. Because of the fear that it is expected to be done quick.
I should unlearn that. And learn to communicate the time it really takes: at least doubble the amount of time of what you're thinking it takes.

For me I went from 10 times the amount to 4 times the amount what I think it ll take
I think it is one of the hardest skills to get

That's one of the hardest things for me, even after all these years.

the fear of not being good enough....
because you parents raised you in that way, that made you believe deep down inside you, that you'll only be loved when you deliver: good grades, be quiet, behave, be a good kid.
As an adult that feeling is still deep inside you, it has become quieter. But still it's that ugly little voice back in your head, that ego dictator that is demanding to do things in a certain way. Like setting work estimates too short because you want to impress your boss or client. To be a good kid.

Well on the other hand I'm pretty motivated when the deadline is close