If this is a "trick question" it would be one birthday, because you are only born 1 day. however, if your talking about actual birthdays, then it would be just based on the normal life expectancy of a normal man.
All of me by:Richardsin carders
Answer:
You should a design even if it is just something very simple. DO something that you would not mind riding on. Same with the color of the paint. You can do more than one but don't use like the color pink for example unless you don't mind that color.
Explanation:
Remember that you can still ride your bike so whatever you do make it so that you still love it.