I got confused the more... God
Thanks anyway
Some wallets (mostly offline ones) let you have your own keys owned by you alone and you can use these keys to enter your house any time you want. You can import these keys into other wallets which will let you into your house (coins).
True. But an important point is that the exchange does not
give you keys to your house periodically to let you enter - it
comes over and puts the keys in the door themselves. This is the "key" difference here.
There's also a final scenario, which is that someone steals the keys to your house from you (hacks your computer or something, depending on how you secure your coins). Then they can take everything inside.
There are three problems with storing your keys/coins with an exchange:
1. If the exchange wants to throw away the keys, or keep them and access your house without your consent, or lie and pretend that your keys were stolen, they can. If the exchange are monitored by the police it's harder for them to do this, but still possible.
2. Exchanges are a much bigger target for theft than you are.
3. Bitcoin brings independence for money. There's not much difference storing your Bitcoin in an exchange to storing fiat in your bank.