Quite tolerably, those who may have later have the interest with zero ideal can still be skeptic at were they feel doubts or impossible to be true which basically could be acts to their lack of knowledge. You don't scold them rather let them know the fact at the given time if you really have the time to put them through though.
I get your point though, but learning to invest in bitcoin isn't that complex or complicated as most persons think, there are several articles online that could brighten their understand and give a clearer view of what Bitcoin is and how they can interact with it. Or one of the best known methods is watching videos on YouTube which may give a clearer view as the influencer also demonstrates how it's been done. I could remember my first experience using electrum wallet, I actually learnt it from YouTube, and it was extremely easy to flow with.
So I would admit that before involving in bitcoin, your doubts must have to be cleared while you prioritize on trusting the industry and have your funds secured on your self custody.
Investors don't need to clear their doubts before they begin their investment, they can start right away and learn to trust in the network as time goes by. Sometimes over confidence make people to take the wrong decisions and at the end blame bitcoin for their own actions. However the market volatility isn't a new thing and most people with their confidence gets into the market aggressively of which when price start moving against their direction they start to panic and could go as far as selling their bitcoin.