Does it seem odd to track my lifespan?

So I have a widget in my phone's home screen tracking the days I have lived so far, to remind me of the time I have, and not to waste it.I was sitting in the school dining hall, glancing at my phone to check the time and my friend remarked how it is weird that I'm counting the days I'm living.I didn't say anything but I'm confused about how is it weird. We are 15~16 y/o.