I was "not told anything". I analysed the findings and developments of the last hundreds years, and learned from there, taking as proofs what were proofs. Ignoring them would just be fooling ourselves...
Explain to me how any thing can be a particle and a wave at the same time?
You can check out any textbook or online lecture on quantum mechanics. The double slit experiment may be the right place to begin with. You may even start with the wikipedia page and the references therein. It is very well explained.