full of piss and vinegar

Having an abundance or excessive amount of boisterous, youthful energy, enthusiasm, or rowdiness. Although we came out into the match full of piss and vinegar, our team just didn't have the skill necessary to beat our cross-town rivals. It took having kids of my own to remember how full of piss and vinegar a child can be at 6 AM. My college intern is always full of piss and vinegar, whereas I don't have any energy at all until my third cup of coffee.

full of piss and vinegar

Very energetic, quite aggressive. This rather impolite cliché (piss, for urine, used to be quite acceptable language but no longer is) dates from the mid-1900s. Mickey Spillane used it in Death Dealers (1966), “You were young and fast and strong. Full of piss and vinegar.”