Sri Sri Ravi Shankar:
See, if you are able to meditate effortlessly by remembering someone or something, then that is alright.
Maharishi Patanjali has mentioned in the Yoga Sutras (a treatise on the eight limbs of Yoga) that if you are able to meditate by remembering or contemplating upon an image of someone, or something that is very dear to you, then that is alright.
There are many approaches to meditation.
Here (in the Advanced Meditation Course), by saying that everything around you is hollow and empty, we bring the mind that is turned outwards (to the material world) back inwards to its source. When you become aware that everything around you is hollow and empty, then a deep realization dawns within you.
So meditation is that which happens very effortlessly. But if, while you sit for meditation, you make efforts to remember Gurudev’s image and how he looks, then meditation will not happen.
There is a tradition in which people are taught to meditate by contemplating upon some form.
In the Yoga Sutras it is said, 'Vitraag vishayam-va chittam'. It means that just by thinking about an enlightened and dispassionate soul, one can go deep into meditation. That is why one goes into meditation just by thinking about the Guru. This really does happen, and it is alright. But you need not strain yourself so much to think of the Guru in order to meditate.
Once you are connected with the Master, when you heart becomes one with the Master, and when love dawns from within you, then meditation happens effortlessly.
It is how it was with the Gopis (the womenfolk of Vrindavan where Lord Krishna spent his early years), who were so totally in love with Lord Krishna. The Gopis never made any effort to meditate. They were so soaked in their love for Lord Krishna that they would effortlessly slip into meditation. The moment there is deep love, meditation just happens.
The other approach is that which was taught by Lord Budhha. For meditation, Lord Buddha would say that 'Everything around you is temporary and transient. Nothing will last forever. Just remember that it will all disappear one day'.
So this is another way to meditate.