This is the 131st most frequent Czech word.
sebe
"Yourself" or "oneself" (reflexive pronoun).
Here, 'sebe' is in its locative form 'sobě' and is used reflexively to refer back to the subject.
Přemýšlím o sobě.
I think about myself.
'Sebe' in this context is used reflexively in the accusative case to express self-confidence.
Člověk by měl věřit v sebe.
A person should believe in themselves.
In this imperative form, 'sebe' is in the accusative case and is used reflexively to indicate a mutual or self-directed action.