"choosing to become a parent is the hardest thing I have ever done"
Actually, I'd imagine that that bit is pretty easy because the subsequent parts (as described in the article) cannot be imagined before they happen. Thus choosing to become a parent probably looks pretty easy.
I would say that having a kid to me seems like a lot bigger change than getting married. But of course I am married already, so maybe that in retrospect doesn't seem like such a big change...
Actually, I'd imagine that that bit is pretty easy because the subsequent parts (as described in the article) cannot be imagined before they happen. Thus choosing to become a parent probably looks pretty easy.