For anyone not sure why this is not a brilliant idea:

Generating a wallet address DOES have a chance to 'repeat already generated wallets'... The problem only comes in when you actually look at what that chance actually is.
What you're looking for is a RIPEMD160(SHA256(SHA256())) collision. There are around 2^160 possible wallet addresses. To put that into perspective I believe the number of atoms in the observable universe, is estimated to be between 4×10^79 and 4×10^81
What does 2^160 look like?
approx: 1,460,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000