I only realised how much I hid and continue to hide from my parents recently. I think almost everyone does this, so feel free to share your thoughts and experiences below!
#1 Music taste
I never shared too much of my music taste with my parents, I would've gotten in trouble for it.
When I listened to "I kissed a girl" by Katy Perry just ONCE, they told me to stop listening to music promoting the LGBT+ community and took my scented Katy Perry CD away from me.
I love Rap. I always have, it started to gain even more meaning for me when I started to develop an eating disorder, grew more and more depressed, harmed myself for several years and when I was going through recovery.
My parents love Jazz and Soul - they dislike the simplicity of Pop and don't recognize the complexity some good rap songs have. I don't support taking drugs and don't want to do that and for them, listening to rap music is the first step to becoming a full blown junkie.
I love German Rap in particular for multiple reasons, I know that it's embarassing at times, but I still like it.
Listening to Rap when I'm feeling low is a small, but still subtantial part of my personality and identity.
#2 Love life
I guess this is a classic for most kids of rather strict parents - my parents still don't know that I was in a relationship with my ex boyfriend, they met him, but I told them that he was just a friend and they kinda bought it.
I never talked about him ever again, they sometimes ask, but I avoid the topic.
My other "ex" is someone they'd be so deeply shocked about, I always hid it from them - they have no idea how big of an influence that person had on me. He was the most important person in my life for 4 years or so and always supported me. My friends didn't like him, I just completely hid him from everyone I knew at the time.
After dreaming about my parents meeting my boyfriend and falling in love with him as their future son in law, reality crushed me hard (my parents didn't want to meet him, read more about that in this take: How telling my parents about my 6mo boyfriend went (they hate him for religious reasons) ).
I completely cut out my boyfriend from the version of my life I present to them when I meet them or call them. It's like he doesn't exist, otherwise we just fight, so I know that for the next few years, I'll have to lay low about my love life and it kinda sucks.
#3 Leisure time
I used to do a lot of things without my parent's knowledge or consent, especially after getting my driver's licence, I just had to leave.
I was never able to go on dates or to go outside without them knowing, so I mainly laid low and talked to people online in my room.
When I would go out with my friends, I never had alcohol (legal since 16 for me, I don't live in the US), I never had a cigarette or did drugs, so I guess most of how they raised me "worked". I hate alcohol, despise cigarettes and think drugs are the absolute worst option out of the 3 (alcohol is a drug too though).
All my life, I lied to my parents. Some of those lies were big, some of them were small, and although I had a really close relationship with them for quite a while, those 3 issues were things I was never able to open up about, simply because I knew I'd have to face consequences.
I was always told by my parents that they value honesty above all else, but in reality, they always punished me for telling the truth and when I lied to them, they almost never figured it out.
I have taken away from my personal experience that I won't punish my kids for being truthful, even if the truth hurts (unless they do something really bad and/or irresponsible (kill someone, drive under the influence).