Sub-optimal sleep can absolutely ruin you, in the long run. E.g. it's been suggested that a significant portion (a third, IIRC, have to find that article) of chronic fatigue incidents are due to non-restorative sleep. Definitely a problem worth solving if you have it.

If you lie in bed awake once per week or so, you surely don't need to fret about it. It just must not become part of your lifestyle - if it does, get a checkup.