highs and lows

why is it so easy to slide from one end of the spectrum to the other. The day has seemingly gone good but somehow at the end of the day I feel so low......
..for some reason the thought of how good it would be to cuddle with someone at this moment crosses my mind. I have several people in mind, but very well know that none of them are the right ones and will never be and are actually totally wrong for me in everyway.
...you reach a point of wanting the independence, but yet want someone to rely on for warmth, and they both don't go together for me at this point in my life.
...ohh... this path I predict is going to be so long...if administered with all of my instructions to myself in mind and sticking to the etchics right hand.
..I saw a beautiful movie yesterday with a roommate and we both loved it. One of those happy ever after movies "Must love dogs". And I do love dogs, but the movies wasn't really too much about dogs, but all about finding the right one at the right moment....
...just a thought, but could it be that the depth of love increases with the age. I mean do we realy understand how much we can love someone at 18 and for what reasons - as well as we can (or maybe not) understand it at 30? I'd hope that by 30 u've gone through so much and bumped your shoulders with so many other people that you would be able to tell when the right person came in sight...there - that's the one.