Was there a time in your life when suddenly your mind floats to a certain level, as if in a trance? Do you remember some thoughts and events that you experienced in the past? Although you fully know well that those past experiences are impossible to re-live again, still with a mixture of both happiness and sadness, such events bring a smile to your face. Yes, you are experiencing what is known as the nostalgic moment. Sweet memories of the past fill your mind, and you remember friends and places, music and fashion trends associated with such nostalgic feeling.