Too much mana? Am I doing it wrong?

So, in questing from probably 82+, I have never, ever, ever run out of mana.

I mean I blow through every cooldown, use every spell, go all out on the suckers (in questing) through battle after battle after battle. I have to stop all the time due to health. but Mana? After my typical battle, I have 99% mana. It never drops below maybe 95%.

I suppose instances will be different where I can burn mana for longer fights without facing hp concerns.

Am I doing it wrong? Stacking too much int or something?

My rotation is very simple. Mainly FB. When Frostfire procs, I hit that. When ice lance or freeze procs, I hit one depending on the MOBs heatlh (if he's low, I IL him. Otherwise, freeze to prevent damage to my health). Doing that he's usually dead by or at the time he reaches me. I stay at over 95% mana the entire time.

Whats the deal? Back in early Wrath, BC or Vanilla I would burn 50-75% mana rolling 3 mobs like this.

If your mobs are dying in a quickly manner and you're not using a lot of mana, it's really not an issue. Are you using Mage Armor? That will constantly keep your mana full while questing.

Running dungeons as frost will require you to manage your mana.