I'm still awake at neaŕly half past 4, and i don't even really feel tired, and i just realised why - ive been drinking cola all day. I obviously can't tolerate my caffeine 😬
A friend went to the doctors with the same complaint and same cause; also another friend went to the doctor with the complaint 'feel tired', the cause? Had run a marathon 2 days previously (and thought they should've been better by now).