You will notice the negative effect of certain places, movies, music and people. When you go to a place or watch a movie or hear music with a crude or negative atmosphere, the good feelings that you had before, will disappear like a snowflake in a desert. Hanging out with certain people will do the same for you (not the disappearing, but changing your good mood).

Meet people who are also spiritually-minded. Read positive books. Choose with care which movies you watch. Listen to music that gives you a positive or peaceful feeling.

Tip:
Do something to help other people. It will surprise you how much positivity you discover in yourself when you do this. The 'lost' time and energy will be returned to you in a beautiful way.