Every Engineer should pursue the PE in their respective fields. And continue learning after that.
Another way to distinguish true engineers from people who work in the engineering department, is to wear the ring from the 'Order of the Engineer.' The order has strict qualification standards, and the ring is an easy way to identify a fellow engineer.
We must remember that engineers are first scientists. I believe that unless we hold our profession in high regards and esteem, no one else will. We should demonstrate the respect we have for engineering by becoming licensed Professional Engineers.
No one to my limited knowledge has ever regretted getting licensed, however I have met several engineers who regret not pursuing it sooner, and they now feel it is too late.
I have a lot respect for people who do engineering work even though they do not have an engineering degree. I respect people who have the experience of years of work to their credit. I don't deny that some machinists and craftsmen are more reliable to make "engineering" decisions than the engineers who work with them. Still, a craftsman is a craftsman, a machinist is a machinist, a technician is a technician, a detailer is a detailer, a cad operator is a cad operator, and an engineer is an engineer.
Endeavor to be licensed, and if you are not capable of it, die trying. It's never too late. I just graduated in May 2002 with a BSME, have taken and passed the FE, will sit for the PE in 4 years. Today is my birthday - I'm 37, I've been married for 15 years and have 4 children. It's never too late 'til your dead.