The great thing about being industriously creative is that copies of your creative work can be sold again and again for years and years. But do you have ownership? Have you given it away? Or did you not own it in the first place, i.e. your boss owns it?
When I say anything creative, I mean for example books, articles, training materials, plays, drawings, paintings, graphics, music and songs, those photos of the dog all sorts of creative stuff. If you create something good, other people will want it.
At present, you use the creative works of others anyway, and are never challenged, but attitudes are changing. People will increasingly enforce their IP rights over creative works that they own. So will you. Such works are protected by Copyright literally, the right to copy. Normally if you create the work, you have the right to copy it, and have the right to allow other people to copy it. Copyright is a very powerful protection.
If you are a twisted individual who likes to steer conversations towards subjects where only you have researched the answers, then copyright is your chance to shine.
There is a very low test of originality, so you can get pretty close to borrowing other peoples ideas and still come out with copyright works that are all yours.
Now you are aware of copyright, paranoia may set in. Please be assured that not everybody is infringing your copyright, although it is easily done by downloading or photocopying, but not by looking at you in a funny way.
A copyright infringement win can be very satisfying. Not only does it sound great, but it gives the impression that there is something worth taking. However, do not expect to make a financial killing unless you have really suffered tangible loss, and not just hurt feelings.
With the right advice, copyright actions can be settled immediately on the basis of a written undertaking not to do it again. Sometimes there is a small payment, and both parties move on.
With the wrong advice, you can spook the other side, resulting in expensive emergency court proceedings.