Krishna means the most attractive --- the Self. He is the very life force in every living being.
Krishna's blue body indicates the infinity within, like the sky and ocean. Krishna was born at midnight when all the guards had fallen asleep. The guards represent the five senses that keep you busy in the outer world and don't let you experience your Self.
Krishna- the embodiment of ananda (bliss) was born of the union of Devaki, meaning body, and Vasudeva, meaning breath. Kansa, the ego, had imprisoned them. To protect Krishna from Kansa, Vasudeva takes him across the river Yamuna-that symbolises love.
Vasudeva carried Krishna in a basket on top of his head across river Yamuna, in floods and rain. He was about to drown but child Krishna put his leg outside the basket, and the river stopped rising. This means when difficulties come up, God's protection is always there.
Krishna grew up in Yashoda's house. Yashoda symbolises shradha (faith, devotion), which can make bliss grow in us. Then there is Radha, which means longing, that gives birth to love. Radhe is the individual life, Shyam is the infinite life. Radhe –Shyam is the entire creation, filled with life.
Krishna's flute symbolises that when you are hollow and empty, you become the perfect instrument of the Divine and music happens in your life. Krishna's pose, standing with one foot firmly on the ground with the other raised, poised lightly, depicts the way to live life in perfect balance between worldly matters and spiritualism.
To be joyful and happy and realise that you are above all your roles and events, you are the untouched Self. So in Krishna, we see the birth of these qualities in our
human body. You can see Krishna silent like the Buddha, or in the battlefield, or as a best friend, or as a very mischievous child. It is a total blossoming of existence and the symbol of all possibilities.
Enlivening these Krishna qualities in your own consciousness, and letting your true nature manifest is the way to celebrate Janamashtami.