Picture this...
...Your character is fighting a Legendary dragon. It's something you've done on many occasions. You don't even anticipate breaking sweat. You use dragonrend, you swing your trusty mace using a power attack. Ha ha, dragon, prepare to meet thine end!
Several swings later, the dragon takes off again. It attacks once more. It's barely lost any health. What the...? This is one tough reptile. Two health potions later and after nearly dying the beast is slain...wow that was tough.
A little uneasy about how difficult the battle was you take on a vampire...just an ordinary one, nothing special. This is uncomfortably hard too. What the heck is wrong? Have you lost your touch? Is the dragonborn getting a bit long in the tooth? Is it time to slink away from Skyrim in shame?
No...it turns out that I wondered how hard it would be to go from Master difficulty to Legendary a couple of dungeons ago and forgot to change the setting back! Doh!
I've been playing on Legendary difficulty ever since and fretting over my increasing ineptitude. I swapped back to Master which was hard enough and now it seems like a cake walk (almost). I feel like such a berk.
Have any of you made similar gaffs?