When you're working for someone else you're only as good as they say you are. When you are on your own you're only as good as your customers think you are.
Knowledge, experience and being able to think and work your way through anything that you run up against comes with time. The benchmark you should be looking to achieve is when you can go out to work on something you've never seen before and can take your knowledge and experience and teach yourself the new equipment while you work on it. THEN you go home at the end of the day and dig for every bit of information on it you can find and back up your "ideas" with the facts.
Everyone here I'd guess will agree that in this industry you never stop learning. If you worked today and didn't learn something new then you weren't paying attention.