Once a (something), always a (something) proverb
A person cannot change his or her innate or fundamental nature.
He said he would quit alcohol, but he still can't desist from drinking. Once an alcoholic, always an alcoholic.
People lost their faith in this celebrity as they think that once a liar, always a liar.
Despite his old age, he still managed to beat the burglar breaking into his house last night as he used to be a phenomenal boxer. Once a boxer, always a boxer.
The origin of this proverb is not clear.
Something that makes spectators excited and delighted
The garden, full of colourful flowers is a joy to behold.