We are not a perfect person, a careless person leads to a something risk. In crypto world, you always hold your coins but how would you assure that it is safe? Or encrypted? In creating your own wallet you need to keep your private key  save. All the time you need to open your wallet, private key is always needed. Provided by your private keys, you can view or monitor what coins you are holding. If you lost your private key, you cannot recover it. So please keep and save you private keys to be secured.