Mental short circuits - should I be less controlled?

[GexTrick]

Yesterday I was at the hospital for my periodic sex health check, waiting to have my blood sampled.
While waiting for my turn I noticed a personal magnetic card of a gym someone had lost on the waiting room floor. Quite probably a year subscription card since the expiration date was still pretty far.

I took it, asked the guy next to me if it was his. He said it wasnt but there was another guy sitting there some minutes before and it was likely his. Since he didnt seem to be around anymore I assumed he had walked away and decided after my blood sampling I would walk to the gym and leave the card to the staff, but right before I walked out of the building I casually met the owner and gave him the card. 

He thanked me kindly and asked if he could offer me some breakfast at the local bar, I told it wasnt necessary but if it pleased him to do so I would gladly accept and moments later we were having a coffee and a brioche.
We didn't talk much but all the time I fantasized about offering him some head since he was hot, the place increased the chance of him being gay or bi by a significant margin and even the fact that he had offered me something could've been an attempt by him to hook up, but in the end I didn't manage to push my luck and nothing else than the breakfast happened.

The point is: I've been raised to be extremely cautious and discrete when in public as a form of respect for others (definitely not because I am ashamed or insecure about sex or myself). When I'm in contexts I feel appropriate(clubs, baths, or even just surrounded by people I know to have a kinky mindset) I am pretty shameless and slutty, but when with strangers I tend to control myself a lot both physically and behaviorally.

I know this makes me an enjoyable guy for many, but I also cannot but think it costs me chances of fun I otherwise could have, such as this episode. It's sort of a small short circuit in my mind.

Do some of you guys feel similar or have tips (as general as a tip to a stranger could be, ofc)?