Do You Need a Sleep Tracker?

In the biohacker world, these peopleo, they want to measure everything. I don't need a sleep tracker to tell me how well i slept last night. All that matters is how do you feel? That's all that matters. If you're overweight, but you feel great, i got no problem of that. But if you have a medical condition, but you still feel joyous and feeling great, then the data isn't going to shift one way or the other.