Doubtfully Daily Matigo

Burning the candle at both ends is rarely sustainable and I'm wondering if this is the cause for the recent lack of focus I've been experiencing. Regardless of where I am or what I'm doing, the mind will wander mid-process which can result in emails being left unattended, code being half-written, and conversations being tuned out of. As one can imagine, this isn't cool. Is the lack of focus a different kind of burn-out, or is it just a result of getting older?