A3. Even if a person is really able to recall past lives, or not, it has little bearing on one's present search for the end of all ignorance and suffering. Firstly, the past cannot be undone, the present is the moment to do right, to accumulate good deeds and understanding. Regret is entirely useless to the Buddhist, it could in fact distract from the present, thereby causing further unpleasant moments. The present is crucial to right understanding, with which past lives have little to do. Besides, can we really not doubt if someone says they could recall their past lives? Who really cares if they do or not, in the end?

For further reading see "The 2nd Yamakawaga Pathamasamphodhasutta" Samyuttanikaya, Salayatanawagga.