Dolphins are creatures that are thought to be incredibly intelligent. There are pigs which are thought to have the intelligence of a 3 to 4 year old child when they are adults and then there are dolphins which are thought to have the intelligence of an 8 or 9 year old child and this is only from the most limited studies that do not take into account all their various nuances and all of the things that dolphins really know how to do.
If you have a dream where you see a dolphin then this dream means that you need to commune with nature and specifically with the water. There are times in a person's life when the real world can get too overwhelming, and during these times it is best to go have a look out at the ocean to gain some peace of mind from this.
There is also another possibility when it comes to dreaming of dolphins. Dolphins are thought of as being very impressive creatures. They are second to none in terms of their intelligence especially when compared with their fishy peers who for the longest time, we weren't even sure if they were able to feel pain or not because of how minimally expressive they really are. The expressive vocabulary of the fishy cousins of dolphins is severely limited and it is because of this fact that a dream about dolphins can have a really important meaning. They are thought of as being incredibly intelligent and this is well known to humans. Therefore to dream that you are a dolphin, it means that you are being a bit arrogant recently. You feel like you are a little bit better than the others around you and you think that you can do better than them at some specific (or even possibly general) task. You probably have no right to feel so superior though and you should therefore watch your attitude when it comes to things like this or you might end up hurting the feelings of others and causing yourself a lot of strife in your social life which is no good. Even if you consistently perform better than others at what you do, there is no need to lord it over others.
Dolphins are also known for being very good at tricks though and very good at communicating. Perhaps you feel like you have done a good job of expressing yourself recently. You feel accomplished because of your ability to really express yourself and make your feelings known on any given subject. This is a good thing as it allows you the ability to make sure that others truly do understand you. In this world, no matter what it is you are doing, it is essential that you communicate well with everyone around you for even the most seemingly trivial subjects. You simply need to know what you're doing and those around you need to be comforted in your own knowledge of what you are doing. If you don't sound like you know what is going on than others will find it hard to trust you and if you can't establish trust it will be difficult for you to get anyone on your side when you really need their help. If you want to succeed, be like the dolphin, this is probably what your dream is trying to tell you.