Do we experience things of beauty only for short moments or do they make a lasting impression on us?

John Keats starts his poem with the line ‘A thing of beauty is a joy forever’. It obviously means that a thing of beauty is a constant source of joy. He goes on saying that its loveliness goes on increasing every moment and it never passes into nothingness. The beautiful things around us make a lasting impression on us. A person living in the midst of natural beauty always feels happy as he has things of beauty all around him to delight him forever.