Confused by missed win analysis

Hi all, 

I'm pretty new to chess, and now I am more familiar with the game I have been going over some of the analysis details at the end of a game. In the following game my aim was to sneakily attack the f7 pawn with my Bishop and take it with the Queen for check mate. 

I was fairly pleased with how it turned out (although I'm sure it will seem very amateurish), but a couple of moves came up as a missed win, and I just can't see how I could have won.

So this is the first one. My Ng7 move was to attack f7 as a back up Bc4. When it was safe I wanted to move Bd2 to b4 to stop the queen coming out to e7 and to stop Rg1 moving to f1. By making that move now, Nc6 would take Bb4 which I didn't want.

The second one was recommending the same. The reason I moved the pawn was so to end up in an exchange thay ended with my Bishop on b4.

I just want to make sure that I am not missing anything obvious.

Thanks for giving it a look!

Having a plan and sticking to it is great -- overloading what you saw as a weak f7 square. Unfortunately, after 6. Ng5 Bxd2+ 7. Qxd2 0-0, Black's position is absolutely fine, including a safely castled King.

Seeing the benefits of the engine's recommended 6. Bxb4 ... involves looking several moves ahead. For instance, after 6. Bxb4 Nxb4 7. dxe5 .... (threatening to capture the f6 Knight), White is now up a pawn and Black does not have any good options. There are many ways that particular line could continue, so here are several illustrative variations:

(a) 7.... Nxe4 8. Bd5 ... (Black loses material due to the Bishop forking the a8 Rook and e4 Knight. 8... Nxd5 9. Qxd5 ... simply reestablishes the fork)

(b) 7... Ng8 (White controls the center and Black is seriously behind in development)

(c) 7... Nh5 8. Qd2 .... (threatening the b4 Knight and trapping the h5 Knight, which can be won with g4)

(d) 7... Ng4 8. h3 Nh6 9. Qd2 Nc6 10. Nc3 ... (the h6 Knight is placed on a terrible square and Black is seriously behind in development)

So with 6. Bxb4 ..., Black loses material and/or weakens their position as White gains a lead in development, whereas 6. Ng5 ... immediately leads to near equality.

bb4 nb4, qd2 nfd5, ed5 qg5 ... slightly equal

You just have to notice a very simple thing. This is both before you have played Ng5 (which of course could be answered by swapping bishops first at d2, and then castling, when you would have achieved nothing) and after Ng5 Rf8? (a bad move for sure).

That knight at c6 is defending both the b4 bishop, and the e5 pawn.

How can you exploit it?

Sorry guys, only just saw these responses. Thank you so much for your help, I think what confused me is when it said missed win I thought it meant I could win the next move or 2, but I know that I need to start looking much further ahead when playing! Also, my plan was reliant on a human making a mistake, which I guess a computer chooses the best move based on them not making a mistake? 

I'm going to take some time now to process your responses and better understand them.

Thanks guys!

You should never make plans hoping your opponent makes mistakes, because you will eventually reach opponents who don't. 

bf7 ke7 bb4? (idk im kinda new)

"Missed win" is just simply a missed opportunity to gain an advantage.

"Missed mate" is another expression altogether.

(I know that my response is two years too slow)