I would absolutely forget appointments if I didn't keep an up to date outlook calendar.
Forgetting things is human nature. Most people forget to do something on a daily basis. However, when it comes to your livelihood - your future - your career, you should absolutely never forget a job interview. Forgetting an interview is employment kryptonite, even though most people are unlikely to admit to a potential employer that they forgot the interview, employers generally will not give a candidate a second chance if they miss an interview with no prior notice.
Fortunately, even though our human brains may be lacking in the memory department, there is a miracle device that almost everyone has, it's called a cell phone, and with very little effort you can program your cell phone to remind you about important appointments. If necessary you can set an alarm on your computer, your tablet, your oven, your microwave, your alarm clock (if you still have one) and some cars will even remind you of appointments. If you're someone who is devoid of recent technology you can ask family members and friends to remind you - although that is the least reliable method - as we've already discussed, forgetfulness is human nature, if you can't remember your own appointments - how is someone else going to remember them for you?
There are plenty of books available regarding how to improve your memory but with so many options available to help you, there is no need to work that hard at it unless you want to. The next time you schedule an appointment that could affect the rest of your life, do whatever it takes to make sure you keep it.