Do you know how to say “It’s a cinch” in Spanish? That is “dead easy”, “a walk in the park”, “like falling off a log” (I say that one quite often but I do think it must be quite painful), “a walkover” “a no-brainer”. Well, now I’m going to tell you …
It comes from the verb “chupar” which is “to suck” so it relates presumably to something even a baby can suck. Just to be very boring for a minute, the form is actually a past participle “chupado” pronounced in a way that drops the “d” (just think “gonna” in English).
Give it a try some time when something is really easy, or you’re just being ironic about your language skills.