- It often happens that you like several people at the same time, but you only fall in love with one.
In my opinion, I think this is totally false. When you fall in love with someone you don't have eyes for anyone else; all your energies and all your effort will be focused on that person. You want to spend your time with her, make her smile, see her happy. Gal Gadot herself can come in person and you won't care at all XD, since you only care about one person in the world.
What I do believe can happen at some point in life is that you like several people at the same time, without really being in love with any of them (which does not mean that you do not love them or that you do not have some kind of nice feelings towards them ).
Just as the movies paint it, it is not love.
I think this is not entirely true, perhaps it is difficult to achieve a love like the one shown in movies and cinema, but I know people who have been able to live (genuinely) for a long time a love equal to that of the movies (and if it is not the same, it is very close).
- Love is not maintained by magic, you must build it and strengthen it day by day.
To some extent, this sentence is not entirely correct. I think that love is magic, if that indescribable magic is not present, then it would not be pure love. And every day that magic must be present, that magic that floods you is what makes you want to know how that person is spending their day, want to surprise them with details... In short, magic is what keeps love alive (and strengthens it over time). If at some point the magic ends, what remains is habit and routine.
No matter what, it is impossible to get your heart broken at least once in your life.
Personally, I could affirm that the sentence is correct. But no, it is not a law of life, it is not a norm; if you initially fall in love with the right person, and the love is reciprocated, they will probably never break your heart.