Was Tennyson on track with his famous, "'Tis better to have loved and lost than never to have loved at all"? Or was Yakamochi closer to truth with, "Better never to have met you in my dream than to wake and reach for hands that are not there." Regardless, Socrates said it best when he stated, "The hottest love has the coldest end."

It might be a stretch, but I would venture to say that these love quotes could pertain other things in life, besides people. Yeah, sure, you may love a guy/girl (meant as either/or, not a transvestite, although I am sure they are loved too- I've just never met one). But if you passionately love somebody and then suddenly they are gone, it leaves a void in your heart. You can also passionately love an activity or an object, and if you are abruptly snatched away from it, it would leave the same emptiness. Well, maybe not the same emptiness, but just go with me here- I have a point, I promise.
Does a girl who was stricken with blindness at age fifteen regret the fact that she ever had the opportunity to see beauty, now that she's left in darkness? Or does she relish her memories of sight, tenderly remembering what she had? Perhaps, with the right attitude, she secretly enjoys the freedom she now has. Most people will never have the opportunity to 'see' without their eyes getting in the way.* I would imagine that blind people have the capacity to perceive things that us gifted with sight will never know.  In this case, I would imagine that Tennyson overrules.
I'm not one to speak to being "in love", per say, but I have had persons pass on or leave who I cared for deeply, and I know for a fact that I wouldn't trade all the pain and hurt of loss in the world for the memories that we had together.
Overall, I guess that Tennyson takes the cake for being able to put into words something that I am sure many of us have felt. My point for all this, then, is to do everything with all of yourself. Never be too scared to love for fear of being hurt, because life is too short to miss out on.
This is put best into words by Mark Twain, who said, "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowliness. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover."

*Ben Underwood is an extraordinary example of seeing without sight. He lost his eyes at a young age to cancer, and is the only known person in the world to use the reflection of clicking noises from his mouth to pinpoint the location of walls, stairs, doors, people, etc.