It is true that there are moments in our life that we felt we are not happy with what we are doing. But one thing I am sure is that not all days we do have this feeling so we just bare with it and try to enjoy the job that we have.
I agree too that we become happy as we were able to help others. Indeed helping or making others happy will give us a feeling of happiness too.
Yeah, but I don't think making others feel happy is a prerequisite to job satisfaction unless your job really depends on making others feel happy. I think job satisfaction has more to do with aligning your sense of purpose to what you actually do then get remuneration for it.