Thoughts about my profession

I love my profession. It is interesting, serious and I have many responsibilities (A job cannot be "responsible" in this sense. You could also say "the job requires me to be responsible") . It would be nice to reach greater heights in it. I try and put all my powers to reach this aim. Almost all the people in their ("there" is used for the location.) childhood dreamed of being astronauts. But I knew that I wanted to be a customs official . The stable operation of the system depends on the performance of my duties. I try not to let my colleagues down. (you could also say "I try not to let down my colleagues". I presumed you meant to say "let down" which means something like "disappoint" in English)