You're already there. It's just a matter of which viewpoint you're aware of.
Someone that looks like me might be there, but they aren't me. If these worlds are different than ours, then decisions are made that differ from ours, thus our other selves would not be the same. Lives would be different in some small or fundamental way. If i had gotten a job with the utility company some years ago, my life would be vastly different. If i never became an electrician, my life would be vastly different. Theory says each different choice can create another branch reality. If these worlds are identical, then that doesn't seem very fun and a rather poor design...which i don't believe is the case.