What did I say that makes any of it a given? Have you seen how poorly I roll?!

There are still plenty of things that can go wrong and keep us from our goal. It IS still possible for players to die in 4E. I've seen TPKs. I like games where the players feel like badasses a good chunk of the time. I hated in 3E how my wizard would cast his few spells then have to sit back w/a crossbow and contribute very poorly to combat.
Sometimes the adventure means they will be at the last encounter for the princess at the end of their day and if they have had to use more of their dailies already, it will certainly be a tougher fight for them. If they were judicious in using those, things may go more smoothly for them.