Okay, let's not mince words: You tend to exaggerate about yourself, your intelligence, your experience and your expertise as a way to impress people, including your dates and your admirers. And while that may be an effective smokescreen at first, promoting an illusion of yourself that's bigger, grander, brighter than the real you, sooner or later, the truth is going to come out. You're just like everyone else: flawed, nervous, occasionally confused or at a loss.
You don't always have the answer to everything, and you make as many mistakes as the next guy. Will your sweetie think it's cute that you exaggerated things just to impress little ol' them, or will they be annoyed with you for not being honest with them? That remains to be seen, but plenty of people would feel the latter. Real relationships, after all, are about getting real; about letting down your defenses and becoming vulnerable to another person who, yes, might sometimes think you're silly or annoying or boring. But what's so bad about that? Your best moments will shine even more brightly if they're honest, and your sweetie will appreciate your strength in being able to be vulnerable to them.