knowing photoshop is only one of the numerous things you need to know for being a great UI/UX (user-interface / user experience) developer. If Design is what you are thriving along with knowing how to design you should be able to come up with the most desired design for your users. This and some other practices such as wire-framing/prototyping, Research, visual communication and etc. are all what makes you a successful designer.
I suggest you take a look at the roadmap at: https://github.com/togiberlin/ui-ux-designer-roadmap
This would give you a solid idea about what UI/UX designing is all about.