I have been living with bras for most of my life, having developed breasts around age 13. Constant comments about my breasts from school classmates created the curiosity to try a bra in my early teens. From that first time trying on a bra I was instantly surprised how well I filled out the cups and realized that all those school comments, although not given to be helpful, were right that maybe I did need a bra.
At that young age, not only was there a realization that I fit a bra but that there was a fascination in wearing one. It was a unique feeling as a teen boy to be looking at myself filling out the bra cups with cleavage, and seeing my profile in the mirror with the bra on. The feeling of wearing a bra was very positive. I also began to realize that I physically felt more comfortable and put together while wearing one.
Almost overnight I had a big improvement in my self acceptance when wearing a bra. My only hold back was figuring out how this all fit in with social expectations. It was a bit of a conundrum to be a teen who has just realized that they are ok with having boobs and wearing a bra but unsure how to move forward as the real me.
Having had breasts for so long now, as opposed to others developing later in life, it is not something I am overly self conscious about or think about in a social setting. I am comfortable both physically and emotionally wearing a bra daily, and would feel there is something missing if I did not have the support of a bra.
Many here are still trying to figure things out with their more recently acquired features, while early teen developers like me have had much longer to establish what is normal for us. Further, after all the tumultuous comments about my breasts and needing a bra during the school years, my life with breasts after those school years has been very quiet with almost no comments made. By avoiding T shirts entirely, staying with pattern button down shirts, I am not aware of anyone noticing my bra, and feel very safe to wear one daily. If I were to worry about my bra being noticed, it would only be due to close contact such as a hug, and if those situations are anticipated I will usually select a racer type bra which I would guess is less detectable.
As an aside, many on this site have posted pictures of themselves in T shirts over the course of time. I would think that a T shirt would be far more risky in exposing your bra outlines, if that is a concern. If it is not a concern then good for you.
In conclusion, I would say that those who developed breasts early in life during puberty have had a different journey and a much longer time frame to adjust to their reality. Further, if you have breasts you will have bumps up front whether you wear a bra or not. So if a bra makes you more comfortable just do it. If you are concerned about displaying a bra, clothing choices definitely make a difference.
And on a positive note, you may enjoy having those breasts and wearing a bra, which makes acceptance all the more easy.