Oh dear. Why don't you actually research it before making such a statement? Regressions are where the patient experiences the past life and more often than not the people involved have not reached the high state of being a brahmgiani. Does this make it wrong? Does it make it wrong if following a Sikh lifestyle? Research it and find out, these are great questions to ask, don't simply brush them off by saying 'follow the basics', when people come out with big questions it's good....by following up and researching topics like this (without actually taking a regression- just reading about it, or speaking to other people about it) you can understand your Sikhi to an even deeper level as it deals with concepts that are mentioned throughout bani.
Fateh