The pros and cons of falling in like

I've been having a mental debate lately. I like this guy (new topic, right!?). And he's so sweet and so good to me, but I'm not sure how I feel about him. And there's another guy who I have absolutely no business being with, yet for some reason I can't get him out of my head. Then my friend told me about the 80/20 principle. Basically this states that you have a main person, who gives you 80% of everything you need. Then there's another person who gives you the 20% that the first person can't give you. People are then attracted to the 20% because it is what they are missing from the person who gives them 80%. I hope that made sense. Tye Dye is my 80, but Long-boarder is my 20. I'm getting way more from Tye Dye and thus this should be a no brainer. I'm not even sure that he can't give me more than 80%. If I really like this guy, and if he's so good for me, why is my brain putting up roadblocks? Is it something that I need to get over? Do I just need to take a leap? Or am I just trying to sabotage myself?