That's a bad mindset, you are severely limiting yourself with beliefs like that!
You don't have to be some physicist or engineer to create your own synthesizers.
All it takes is some knowledge of basic electronics a breadboard, wire, and components as well as some switches.
Just learn to read those wiring diagrams, know what each component kind of does, and have at it.
Watch some of the videos on that playlist and you will begin to realize it's not really that hard if you set your mind to it.