I appreciate w3w:
自己一开始很有压力。边干边学，去HOME DEPOT买了本PLUMBING的书，看人家是怎么做的；经常去HOME DEPOT看材料，看工具，经常想怎么能把工作做好。我烧的第一份焊，是在我家的凉台上。我自己买材料回家练。到现在，做的很好，很顺。老板很满意。
I agree with Millwright:
我没把那个证当做什么了不起的东西，但我对这种对整体形象不负责任的做法感到生气。急着找工作可以理解，但要掂量掂量自己。真正的license是要经过至少四年学徒的，干过四年和没动过手的不能同日而语。仅凭那苍白的证书我看难以跨过这个门槛。证书=工作？No way!
I didn't tell employers that I had license when I was hunting jobs but didn't think I could handle a licensed job. I did related jobs for more than a year. I worked hard and learned related skills from every opportunity. In this way, when I finally got a license job, I had the confidence to do it well in a short period. Because I knew I shouldn't be less smarter than the average trades people. I did do excellent jobs soon after hired. I am still learning everything new to me. I will definitely be the best in the organization.