Louis Pasteur, the great scientist, said "chance favours the prepared mind", which is a posh way of saying 'do your homework', but it's an excellent piece of advice.
Here's my advice to you: don't marry until you can tell yourself that you've done all you could, and until you've stopped loving the women you've chosen, until you see her clearly, otherwise you'll be cruelly and irremediably mistaken. Marry when you're old and good for nothing...Otherwise all that's good and lofty in you will be lost.