What if the Bitcoin was in notes and with the same value as it has now, do you think anyone would misplace it or even walk with it on the street. Eventually you see a Bitcoin note will you return it to the owner. Let's be sincere and also see it as fun.
Well, I'll Ignore this as just a side comment and not a factual statement, I think you should go back and read the bitcoin white paper and also the features of bitcoin and the solution it carries with it.
Bitcoin was created for decentralization, transparency, anonymity and privacy purposes to mention but a few. Now could all these be achieved if its in paper form, Hell No!. Fiat can never be decentralized because its easy to gather them together and subject it under governmental control, furthermore the government can regulate its distribution from whatever banks issues it, thereby defeating the sole purpose of its creation.
Bitcoin is a digital currency which places people in charge of their money, like you're your own bank manager and you have access to your funds anytime any day as far as you've Internet, your wallet isn't compromised by fraudsters and you've not left it in an exchange which is centralized and can sink your funds upon closing down.