To be frank if his piece looked bad and he told you to forget about making a piece look natural and nearly undetectable then he was certainly not the best in the country. What country are you in?

If you have good side hair and wear a modern age apprproate style with the hairline covered or partly covered it is super easy to get it to look completely natural. If you get good at hairline attachments you can get a really good looking fully exposed hairline style too. I wear both, depending on how great I've done the hairline. I've been with my fiance for 3 years and living together for about half that time nd she does not know I wear! She thinks I color it regularly and cut it every week and that explains why it never gets much longer or shorter and why when I get a new piece it looks slightly different. But I cut it in myself and cut my natural hair every 3 days and have it down to a routine.

If you're lucky enough to have good side hair a topper can look amazing with a good cut in and regular cuts of your own hair (just buzz the back and sides every few days with the same length guard each time while wearing the topper). If your side hair is not so great you can get a full cap although I personally have never seen a really natural looking fullcap.

It can look completely nautral and change your life for the better. It just takes effort.