Problem with understanding "game analyze"

When you made a bad move, and according to the computer, it suggested something different, it tells you what it suggested, and then the following moves...

But when your opponent made a bad move, it also suggests what THEY should've done, but then, the following moves are different sometimes from what the original would've played out. 

For example, in one of my computer analyzed games, it told me "Nf3" for what I should've expected my opponent to do (after my bad move) but then later on, on his bad move it said that he should've played his Knight to a completed new DIFFERENT square. One that, in which this case,.....wasn't to the f3 square.

So how can I trust computer analyzes? I'm sure there is an explanation. Can someone fill me in on a easy to understand idea that would give me insight? I need to trust computer analyzes so I can get better at my games...

Thanks :)

Computers just show the 'perfect' move. So if your opponent's follow-up move is different that means you've just gained a (usually tiny) advantage in one way or another.

Ok. Thanks QueenOfTactics

Try understanding the meaning/reason of the suggested computer move. Sometimes such a thing does not exist, but anyway...

If you fail, either ask a player stronger than you, or ignore it. Adopting computer moves without understanding them is a very bad practice.