Why do I feel like this wont last long?

I've had a lot of blogs, meaning I have tried out almost everything from livejournal to wordpress, to tumblr, etc. I've never committed to one blog, except for tumblr, which I had for almost a year now, and still using it. Even though I absolutely love using tumblr, it doesn't really offer a good "writing" section, it's more for fun stuff and pretty pictures.. so I thought I'd give this a try :) It can't hurt right? I just hope I won't forget the password.