Flood was one of five Tigers to suffer Grand Slam heartbreak at the new Lansdowne Road as England fell to a 24-8 loss to Ireland.
Flood and his Tigers half-back partner Ben Youngs endured a torrid afternoon as Ireland ended England's Grand Slam dreams.
But Flood is adamant lessons as he prepares to return to the scene of the England horror show on Saturday.
"Lessons have been taken on board, although it hasn't led to me lying awake at night questioning myself as to what I'm about," said Flood.
"Of course, it was a huge disappointment and questions arose around myself in terms of what I'm doing. But you have to accept it and move on.
"Everyone told us that Ireland would come out firing and tear us to bits. That's exactly what happened. And it's going to be like that this weekend. It's good knowledge to have, a sense of the ferocity of it all, the aggression.
"Leinster are similar to Ireland. They want to hold you up in the tackle, win that collision. We've got to be ready for that physical challenge.
"It taught us that it's important to try to rein a game back in, maybe to try and calm things down for 20 minutes or so.
"Our aim with Leicester is to keep it a one-score game and then turn on the pressure in the last 15 minutes."
Ben Youngs let his frustrations get the better of him in the RBS 6 Nations clash and was sin-binned after throwing the ball into the crowd.
But Flood is confident Youngs can handle the Dublin cauldron.
"Ben's incredibly strong-minded," added Flood. "Either that or he's not got a clue about what's going on. He just lights up the park."