Treat your patient's as you would want to be treated. Respect goes a long way, especially more so in a psychiatric setting. And be kind to your psych aide's (nurse aide, psych techs, etc.). They spend a lot of time with the patients and can tip you off on behaviors.
I started my prerequisites at age 31 and began the program at age 33. I'm currently 35 and beginning my nursing career. I have never regretted my decisions! I have a background in the financial industry, which bored me and more recently I have worked part time in a hospital. My life experience has made me more appreciative of the work that I do and has given me a much more well rounded and down to earth approach.