Hi
If you have oversetted a pin, others might not bind at all.
Sometimes if your focus is lost, easy locks become allmost unpickable.
And sometimes I find that for some unknown reason I just can´t set the pins. Maybe I´m too heavy handed or something. After taking a break, or doing something different for a while it may become easier. Then again some days seem to be bad for picking. ...psychology I quess.
Couple of locks that I was picking for a week or two without success opened easy after I had two days away from picks.
It all comes with time and practice (I hope, I´m not that good yet).
Happy Picking!
-Wizer