I still use my alarm clock, and I think I will forever do. Sometimes, I just can't completely rely on my biological clock. It betrays me often, that I end up cutting my classes or going so unprepared, such in a rush that wouldn't be able to take a bath and not being able to eat before leaving to school, and if things like this happen, I just feel bad the entire day. And since I have been using an alarm clock for almost all my high school and college years, I have already developed the practice to always set up before I sleep. I just can't sleep setting it, even on the times that there's really nothing important that I would have to require myself to wake very early.
Alarm clocks are the most simple thing, but really effective. Sure, they can be traumatic haha, that ring means the end of the rest for us, but if we think of it they are really effective and they cost nothing, one AA battery per year or so.
