Answer:
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
My days are numbered.
I have a head, tail, but no arms and legs. What am I?
What kind of dog keeps the best time?
My first half means container. Not a lot of people understand my language. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?