Hi,
I am a senior in high school and I have written a couple of drafts for my CommonApp essay. I chose the first prompt and I have written about, well, my life. Since I was born, I have constantly travelled to new places every three years due to my parents job. So I thought that since that it a big part of my identity, I thought that I should write about my essay on that and how such a lifestyle has created my identity. However, while I was surfing on the net, I saw multiple articles saying that our essays should not be about travelling; although, they were talking about a vacation or a short journey. So, just to be sure, would it be advisable for me to write about how I have lived in many places (each for approximately 3 years) and what I have learned from each place that I have stayed in?
Thanks! 
Any topic has the potential to be done well, and your topic by itself sounds interesting. The “cliched” essay topics are just harder to do well and are less likely to stand out, which is why they aren’t encouraged. But if you can make the essay very detailed and engaging using descriptions, dialogue, etc. and also articulate some non-generic things about what you’ve learned from each place, the essay will be great.