After reading about all the hacks I created a passphrase that I cant remember.
Are Coins lost forever in the blockchain?
There must be a lot of coins in this state… Is there any way to see what coins are active?
Trying to retrieve these coins via the public key would break the security of the whole network??
If I know 80-90% of what the passphrase is… Is there a piece of software that can brute force attack using my knowledge of the passphrase as a educated library attack??
If you have encrypted your Bitcoin.org wallet with a passphrase, then only having that passphrase will allow that to be decrypted.
If you have a backup of your wallet prior to performing the encryption step, then any coins from that wallet that still have not been spent can be recovered.
Otherwise, without that passphase to open the wallet you cant get to the private keys inside the wallet, and thus cannot spend those funds.
There is no difference between "lost coins" and "unspent" coins, so no there are nothing more than anecdotal evidence as to how many coins have been lost.
There are ways to try to recover your wallet based on hints about what you remember about your passphrase.
