Hmm. Are you by chance on any medication? Stimulants, or anything else-- even a sleeping pill?
'Sage is used as a nootropic for its acetylcholinesterase inhibitor properties. An "Acetylcholinesterase Inhibitor" promotes the availabilty of Acetylcholine. '
If you are, be wise to limit your intake of Sage.
'Modern evidence supports its effects as an anhidrotic, antibiotic, antifungal, astringent, antispasmodic, estrogenic, hypoglycemic, and tonic. In a double blind, randomized and placebo-controlled trial, sage was found to be effective in the management of mild to moderate Alzheimer's disease.' -
http://en.wikipedia.org/wiki/Salvia_officinalis#Medicinal