I have to say I don't get all this 'you must lie to toddlers business', I don't find I lie about those kinds of things at all, there's rarely any need to, a child-sized version of the truth will usually fit the bill.
It seems odd to me to lie about some of this stuff:
The injection will hurt quite a bit, but it will feel better again after and you'll get a sticker. It will stop you getting poorly which wouldn't be very nice at all.
It really hurts doesn't it, it will do for a minute, then it will start to go away. (If it doesn't, they get paracetamol, which will help it go away!)
I wouldn't say I'll help in a minute if I wasn't going to. I either say it and mean it or say I can't help you right now, you'll have to try by yourself.
If you chew your nails they could bleed and hurt you. It's not good to put your fingers in your mouth all the time because that's how you can pick up colds.
Seriously why lie about any of that?! Bonkers. Why not the real reason? Some occasions where a truth is too big or too painful for them to cope with, yes a temporary white lie may be kinder, but I think those occasions are not every day and you use your judgement on when they are necessary.
I like playing pretend with magic and reindeer, but, no, I find it a bit much when people continue it at all costs, lying when children ask, making more lies to cover the original lie etc. There is a middle ground where you can enjoy the fantasy without constantly bending over backwards to put one over on them.