Up to his armpits in flood water, flanked by darkened buildings and submerged vehicles, Iraq veteran Peter Meijer felt oddly at home Monday night as he trudged through the streets of Brooklyn at the height of Sandy’s fury: “The right place at the right time with the right mission.” With a fellow veteran at his side, Meijer had driven a van from a Brooklyn high school-turned-evacuation shelter to the Gerritsen Beach neighborhood, stopping only when the van’s tires met the storm surge. From there, the pair went on foot.