Wondering whether or not someone is Mr. Right means he's not. It really is exactly that simple. When you've met or gotten to know Mr. Right, he'll be so Mr. Exactly Right that you'll know it like a lightening bolt to your chest. You'll no sooner be able to wonder whether or not he's Mr. Right then you'd wonder, standing out in the rain, whether or not you're getting wet.
You'll know. (And this is all true for men wondering about Miss Right, too.) In love---as in virtually everything---listen to your heart. Sure, it's a doe-eyed cliche. But it's true. Your heart knows. Your brain will do as brains do, and kick in with all kinds of noise and nonsense. But listening to your brain about such things is like listening to Bozo about blending in. Forget it. When considering if a certain someone is the certain someone, kick in with the only evaluative faculties that matter in such matters (or any matters, really): Your instincts.
It's like with God. Think about God, and you get about nowhere. Feel God, and he's on you like yellow on mustard.
Think about whether you're in love with someone, and good luck. Feel whether you are, and you'll know it like you know your name.
Then all that's left is to obey what you've learned, to do what you know is right. And therein so often, of course, lies the rub.
Related posts: God Doesn't Care If You're Married or Not; You! Get Married! Now!; Looking for Mr. Right? You're Missing the Point, Missy; Six Tests to Determine If He's Mr. Right; To Single Women: Men. Don't. Change.; Surprise (Or Not!)! Men Are Spoiled; Top 10 Tips for Becoming an Ideal Husband; What's In A Word: The Truth Behind Men's Personal Ads.