Signs you might be having a stroke. Some people have muscle weakness before they have a stroke. The burning toast thing is also possibly a symptom but it might also be an old wive’s tale.
For what it’s worth, when I have too much caffeine I smell a weird smell that isn’t there, so it’s possibly true.
I've only heard the burnt toast thing in relation to a patient Dr. Wilder Penfield treated for recurrent seizures, where she would smell burnt toast before an episode. This led to developing the Montreal Procedure for epilepsy treatment.