The Buddhists say if you meet somebody and your heart pounds, your hands shake, your knees go weak, that’s not the one. When you meet your ‘soul mate’ you’ll feel calm. No anxiety, no agitation

This is likely a made up quote. Buddhist preach non-attachment above all others things. This is confusing to some people because they think it means shunning friends and family and “lowering” them to something “less” than they are. Not true. Ireality they are arguing that you should love each and every person equally. Treat a stranger the same way you treat mother. Treat someone who doesn’t like you how you would treat your wife. When you love all beings impartially and to the fullest extent that you can, attachments to individuals become unimportant.

As far as being assigned to a soulmate… Buddhist believe that we have all existed - forever. We have all been born and reborn - so many times - that at some point in your past your mother was your son. And your wife was your father. And your neighbor was your cat. And your daughter was your brother. And on and on and on…