I the ladder

You have started climbing
I will lead you to the top
Yet, you won't know
how many steps more
you still have to go
till you finally get
where you want
because the top floor here
is unfortunately missing
you have to keep constructing
one by one as you climb up
But don't be proud
of your achievements
or plan to rest on your laurels
if I can lead you to the top
I can get you a great fall too.
I don't know if then
Will you lose your life
or break your leg.