Full fledged adjective
Completely developed, trained or qualified
He has graduated the University of Law for three years. Now he's a full-fledged lawyer.
How long does it take to become a full-fledged doctor?
Indicates that something which initially seems bad but harmless can become much worse in the future or lead to a harmful development
One's advantage due to their extraordinary skill, ability, or resources.
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.