Only when I'm really motivated to do something. Otherwise, the slightest obstacle will see my interest wane.
How stubborn would you consider yourself, and do you think it's a fault or a virtue?
_________________
It is easy to go down into Hell;
Night and day, the gates of dark Death stand wide;
But to climb back again, to retrace one's steps to the upper air –
There's the rub, the task.
– Virgil, The Aeneid (Book VI)