Thinking patterns, overall suggestions

I'm pretty new to the forums, but I've been lurking for a while.  This is one of my first games in a few months.  Here I am black.  (I am a firm believer that white and black are two different worlds as white dictates and black responds).  I've never taken any classes.  I learned how to play when I was like 5 years old that was 20 years ago.  I feel a bit confident in my play but I'm unsure of how my thinking pattern and playstyle could use improvements.  Should I do more proper/orthodox movements? 

I remember playing this one guy who agressively attacked the side I castled on.  He arranged his pieces in order to move easily If I castled he would move that rook's pawn up every time and use pure pressure from his strong pieces to force a fumble.  I think my style is slightly more passive, should I be more agressive? 

Even though I won the game, he posed some pretty good threats and choices along the way, I think this one shows the best of where I'm at skillwise.  Any advice would be great.

black might have played bishop to h3, so it would remove the mid pawn of the king defense, instead the castle was weak. why did black castle to a abandoned stronghold with no pawn defense ??

The bishop exchange.. well there is some slight advantage sometime if he will endup with a king side castled pawn g6, but since g6 hasnt been played, its an exchange with no purpose i think, so better moves could should have been played instead.

if you played back, castled and wrote back to begin strategics.. then think thats each game depend on the openents next move, not about what you had in mind in the past. I make such errors too sometimes, like having in mind to do a certain opening, the oponent doesnt go for the right answer, and i stick to the opening book and so, i go in a position that isnt made for the situation. Its better to play with an openview and always play the game in front of you, not another game from a book that doesnt fit in, or past memories from when the board looked differnt.  (but as i told i have such errors too)

white had a great attack and blew it. For instance 25 Qe6+ followed by Qxc6 seems to lead to an easy White win. 25 c4 is a horrible blunder

I did not like Black's capturing the b2 pawn. With your King on the Q-side you do not want to give White any open files to attack with.

in opposite side castling games the goal is to break through the enemy's king's pawn structure with pawn pushing.  so your castling queenside was reckless since your pawns were already lacking and weakened. you also rejected opening up lines to the opponents king later on because you felt the pawn formation was important.  try to develop every piece too since it took about 20 moves for you to move your kingside knight.  i have heard "knights first then bishops" in teaching opening theory to beginers.

So 7...Ngf6 was better than Ndf6 - you save the pawn and don't give his knight that square.

As others have pointed out, 12...O-O-O was a mistake. it is really no safer there than in the centre. You want to escape kingside (playing Ngf6 on move  7 would have allowed that). Be very careful of pushing pawns in front of you king. You will leave behind holes for enemy pieces to occupy very close to your king which can't be kicked out by your pawns anymore. They will be permanent and deadly. Also, by pushing the pawns, you open up lines for bishop and queen to slice right through your defences towards your king. You basically gave him a very clear, easy target.

On move 13, don't "test" your opponent to see if he'll make a mistake. Just play the best moves. Ne7 springs to mind. Connect your rooks, prepare to cover up your exposed king and lock things down.

14... Nh5 was a surprise for me. Nd5 was what my intuition said was preferred: from there your knight has better centre control, which you seem to value, and it can go kingside or queenside. Maybe you have an idea that I don't see - I haven't looked hard at this game.

After that the game is all tactics. Just give it to the computer to analyse and find all the combinations.

So, I'd say pay more attention to king safety, make moves that improve your position, not ones that just put the ball into your opponents court, hoping he'll mess up and not hit a winner. Finally, move 7 was odd. You should be looking for moves that develop your pieces, and Ngf6 should have jumped out at you right away.