I've always felt that you dress should reflect the way that you live (or want to live). Clothing/presentation is in a lot of ways aspirational - it puts you in the right mindset to go about doing what you want to do, because you are dressed for it. I recently read something that Wei Koh (of The Rake) wrote - I don't have the exact quote but it was along the lines of how he saw clothing as something that gave him "access". Access to a group of people, a culture, etc.

So, aside from being a firefighter, who are you or who do you want to be? That should hopefully inform the way you should aim to dress. If you're someone who enjoys having an active outdoor lifestyle (dog, hiking, etc.) you shouldn't have a closet full of bespoke suits and italian tailoring. On the flip side, if you're someone who is frequenting art galleries or cocktail parties, a closet full of Lululemon probably won't do the trick. Of course, there is always crossover but I think aligning your wardrobe and your lifestyle is important to feeling comfortable in the clothes you're in.