We all have some amount of anxiety in terms of not wanting to be disappointed by the other person. The question is how serious should you take the person? Just because someone says, "I love you" does it mean that it reflects their true feeling? If the person goes MIA without any prior notice, that's your cue.
Don't rely on this person for your happiness the moment they say those three words.
To answer your question; no. We're all afraid to get our hearts broken. The chances of it ending up poorly is quite big, but also the possibility of things working out perfectly. Love isn't a science, there's no sure way to succeed in it, or even explain why we like some people, especially ones we shouldn't.
They other's are right, just because they may win your heart, they don't deserve your head. Don't throw yourself in without any idea of what you're doing. Be careful. Trust as respect are both things is something you need to earn, just remember that. I can't promise you a life free of pain. That's not very realistic, but you live and learn. Eventually you get it right, and it just seems like the easiest thing ever.