I started working in a company about 3 months ago and it's really been challenging and frustrating having zero experience and background in my current field.

Sometimes, I feel really bad because I feel I should know more than I currently do about the job. I put a lot of effort into learning new things but i don't think I am where I want to be in 3 months on my "growth curve"

How long did it take you to get a firm understanding as a fresh hire with no experience or background related to your job?