Right from the start, they will start telling you that you are soulmates, you belong together, you connect in a way nobody can. But do you really know them?
Ask yourself: what did he share about himself, his family, his past? If you notice that you are the only one sharing and he is only going on and on about how incredible you are, he might be avoiding talking about himself.
Feeling some sort of connection and chemistry at the beginning is normal. But you have to be realistic about everything and see if you really know the person or whether it is just something that he has you believing.