As we all know , swami Vivekananda had unvanquishable, unbeatable memory power. I am practicing Raja Yoga, which is regarded as first step towards that. Essentially — Truth pill is hard to swallow. But still it is the truth, and we have to accept it. As Swami Vivekananda said, society or culture or religion fall in line with Truth or perish. But Truth never comes under the sway of anything. Check the following link on Swami Vivekananda's views on his memory power and Brahmacharya. But for people like us, we need to accept the truth as the ideal. But practice things slowly, steadily and attempt things as far as possible. Never attempt such practices for quick results. It takes some years of practice, as told by Swamiji to cultivate and develop such a memory power with our own efforts. But it is clearly possible. It is science(means, not just human imagination, but a demonstrable fact).