I'm not saying it was wrong, because you were just a kid, but what you are describing is not role-playing. You were making decisions based on your own, out-of-character opinion of what is cool. Role-playing is defined as making decisions from the character's perspective.
The in-character perspective would be to look at what the character knows, and determine what the character would do based on that information. The character can observe that a long sword causes more grievous wounds than a short sword does, increasing the chance of felling an opponent, without a meaningful depreciation of applicability. The character can see that muscle mass improves the ability to wield a long sword, in ways that nimbleness does not, and thus chooses to exercise in the appropriate fashion such as to gain Strength +2 upon hitting level 4.
The characters are aware of the in-game reality which the rules reflect, and given that I won't make a character who is suicidally incompetent, there is no conflict between Optimization and Role-Playing. A character who chooses a sub-optimal weapon, merely because it is "cool", is a fool and a liability that shall not be suffered by the other individuals in the group.
Seriously, building an incompetent character is a jerk move to everyone else at the table. Don't do that. If you fail to kill the dragon because your sword only does a d6 instead of a d8, and then the dragon breathes fire and kills the whole party, then that TPK is entirely your fault and you should feel bad. There are millions of ways to build and play a character that isn't incompetent; it is not a meaningful limit on your freedom of expression.