Conflicting information = I don't know what to believe!

Am I alone in this?  I've come to realise it more and more recently - but looking back, I can see it's been a feature throughout my life.

That is... being told something by one person or authority, only to have another person or authority contradict it - and each person saying that the other is wrong.  This ends up with me not knowing who or what to believe.

Four examples from work recently:

1) In Health and Safety training, it's impressed upon me (it's commonsense as far as I'm concerned) that I shouldn't use any electrical item with a damaged or frayed cable, and that I should report it and get it replaced.  So... one day, I'm using an electric hoist and I notice that the control cable is frayed through to the bare wiring in a couple of places, and in one place there is actually a copper wire exposed.  So I ring the onsite engineers who come and have a look - and they tell me it's perfectly safe to use!  I tell them what I've been told - and what my own commonsense tells me - but they insist that it doesn't need repairing or replacing.  Again... "It's perfectly safe.  Even putting insulating tape on it will only make it worse."  Result?  I refuse to use the equipment, and have reported it to a higher authority.  But other staff are listening to the engineers and are continuing to use the equipment.  Who's right?  The trainers, plus my commonsense?  Or the engineers, who should know better than anyone because they're electricians?  Why would they put someone needlessly at risk?  I'm now beginning to feel like a trouble-maker for going above people's head to get clarification, or a definitive answer - which I think is needed over something like this.  Electrocution risk, fire risk, and so on.

2) A client comes in with three Schedule 3 Controlled Medications.  I'm told to lock two of them away securely - but the other one is alright to keep out, in the client's bag.  I protest that as they're all controlled, they should all be locked away.  But no... I'm only to lock away two of them.  In the end, I go to a pharmacy and ask.  I'm told X and Y are controlled, and need to be locked away - but Z, even though it's similarly controlled, only needs to be locked away at the discretion of the individual in charge of administering it.  So, if that's me, I'll lock it away.  If it's anyone else, they won't.  This seeming anomaly makes no sense to me.  It's either one thing, or it's the other.  The other staff, though, think I'm wrong to insist all the controlled meds should be locked away.  They leave the one med in the client's bag, where anyone could get to it.

3) I notice that the changing table in one of the bathrooms seems to be rocking unsteadily - something that I'd not noticed in the few other times I'd used it.  I check underneath, but can see nothing loose.  I mention it to another staff member, who says as far as he's concerned it's always rocked like that.  A further staff member confirms it.  But then a couple of other staff members I mention it to go and take a look and say it's never rocked like that.  So they start arguing it out.  I start saying my piece, but then I'm looked at as if 'Who are you?  You've only been here five minutes!'  And then I begin to feel bad again because I've sought clarification about something from another source. 

4) A client's care plan says that they're intolerant to lactose.  I see someone giving them milk.  I point out that I'd read in the care plan that they're intolerant to lactose.  "No, they're alright to have some milk."  "But it says 'Avoid dairy products'."  "They've always had milk before."

This extends - for me, anyway - into most other areas of life.  I ask someone to show me how to do something, and they do.  Then, the next time I'm doing it, someone else comes along and says "Why are you doing it that way?"  "Because it's the way I've been shown."  "No... you should do it this way."  So they show me a different way of doing the same thing.  Each way works.  So why is one way better than the other?  No one seems to have the answers.

I simply can't deal with contradictions like this.  It's one thing to have opinions that you stick by, and which others may disagree with.  But quite another for there to be disagreement over important things like safety measures and medications.  "It's safe."  "No, it isn't."  "The engineer said it is."  "The trainer says it isn't."  "Oh, just ignore the trainers, the electrician knows best..." 

Gah!!