And I feel a bitcoin address will be good forever.
But if you want privacy, you need to use a new address for every new transaction.
That's what recommended by bitcoin creator too.
For greater privacy, it's best to use bitcoin addresses only once.
And changing them at every new payment and then throwing them away forever makes me feel like a huge bitcoin-addresses-waster (although I know there can be 2^160 addreeses).
Even you create millions of addresses and never use them, you don't waste anything.