When you grow up in which age you get shame feelings or embarrassment?

It depends on how you were brought up. I grew up in a large family in a small house where infrequent/accidental nudity was common and not a big deal. But yes, sometime in my mid-teens, I became very self-conscious about being seen that way. I wouldn't call it "shame" (like, why should someone be ashamed to be what they are?) so much as being embarrassed to have put others in the situation of seeing me that way.

I must have been 7 or 8 when for the first time I felt embarrassed to be seen naked by my dad, and a short time later I also didn't want to be seen naked by my mom. Since going to gymnasium (age 10) I insisted on locking the bathroom. Most embarrassing moment was when mom took me over the knee for a spanking. But that's a different story.

From the time I was 8 or 9 until I was 17. When I was 17, after my junior year in highschool, my parents took my sister and I on a tour of Europe. We went to France, Switzerland, Germany and Italy. My sister and I spent a lot of time sunbathing on the beaches, at the pool, on the piers and docks at the lakes and on a floaty right off shore at one of the lakes. My sister and I decided that seeing we were in Europe we might as well sunbath like Europeans, topless. We talked it over with mom, she was okay with it, she'd already done it herself when her and dad came over in the early eighties, before they got married. Needless to say over the two months dad saw the boobs enough that he got over them. Now when I sunbath topless in the back yard or on the dock (we live on a lake) it doesn't phase either of us nor is there any concern when I walk around the hallway topless after a shower.