Currently at our company, we have a team of 3 developers. We each have our own projects that we work on. So, we never have more than one person working on a software development project at the same time. Once in a while we may have a developer go and modify another developer's project (months or years down the road).
We follow the waterfall methodology very closely, and it works well for us. We are given a set of software-design specifications that stay the same for 30 years (or longer). Once in a while there may have been a typo or mistake with the design specification and the requirements may change slightly, but this almost never happens.
We do get bugs in our software, but these are typically reported quickly by our small user-base (10 - 15 people) and fixed right on the spot. We then release a new version of the software with the integrated changes very quickly, and never have to do anything again for years.
We have Git repositories on our company shared drive that we use to maintain the software versions and keep track of changes.
I brought up the idea of using a continuous integration with something like Jenkins and was told it wouldn't be necessary. Given our environment, should we be using CI?
Additionally, I would like to know how it will affect me personally if I never learn CI.