OTB-game I won

well done!why did you play 5.) ...Bd6

Im asking as I still have lots to learn

21 Se4 viste seg å være fatalt, han burde ha slått løperen. 

Den dronning tårn  pinninga var nok ett trekk som ga deg en god fordel. Det kan tenkes at Isak ble litt skjelven av det slaget og flyttet ugreit direkte etterpå. Jeg vet med meg selv at det lett blir kokt i hodet rett etter en smell. Det lureste er å gå fra bordet i ti minutter uten å trekke, for å komme litt til hektene.

Han sa etter partiet at han ikke hadde sett 21).... f5.

I played 5.) ...Bd6 in order to develop, in order to protect e5, and because I wanted to castle.    

I get that but that blocks your d7 pawn

and hinders developement of your c8 bishop

I think your pinning and winning the rook for bishop have disturbed the thinking of Isak, and made him more vulnerable, and that is why he didnt see in advance 21 f5. I have noticed that many players gets disturbed in their thinking immediately after they have been tricked. I have that problem myself. I also think that you are good at traps, they are not easy too see, because it usually looks like there is another ok plan with the poisonous moves. You also are good at traps because you are a very smooth , fast developer, and therefore gets the pieces located well, which gives opportunities.

I know, but still I thought it the best move  ....

i see...im not trying to judge you or anything,just trying to learn

This is the best way to learn.

Maybe it was not a good move, but it was the best move I found during the game.

Tha same move in another game:

 http://www.365chess.com/view_game.php?g=3516712

Not a common move, but black won this game.