I do not think humility means that one should automatically put down one's own ability. That's more like an inferiority complex to me.
I think that many people give short shrift to one's abilities and doing so does no good. Inasmuch as accepting what one can't do is an important step in one's training, I also very much believe that accepting what one can do is, perhaps, even more important.
I have to fight the "I suck at kata" attitude I developed in Judo days (in the 70s, kata were that PITA you had to do to pass a grading, and got in the way of randori - at least that was the attitude at our dojo). As a result the bad attitude towards kata, I struggle to see the point of memorizing a set of 13, 31, or 70 moves with a jo, or a jo, or a bokken, respectively. So I don't do well at recalling them - even after a whole lot of practice... I can follow along most of the time but...
When it comes to people telling me "I CAN'T (do whatever)" my usual response is along the lines of "perhaps not yet, but you haven't learned it yet" or "yes you can, you just haven't learned how yet"
Maybe I should take my own advice.
Three things for beginners after a little primer on dojo etiquette - basic levels of:
Ukemi (also used as a form of conditioning)
Ikkyo and taking balance toward 'the third point'