After only reading bad things about guys in love how do you believe a guy when he says he loves you?

WEll me personally as a guy think that most of us are a bit to hormonal so if all of a sudden he just says i love you for no reason and just well says it to make you feel like kissing him or something then i would basically dropo the guy. But if you have been going out for a while and he says it in the right moment and doesnt look for a kiss or anyhting or he says it over the phone i would think the dude is a pretty cool guy.