Hey Daniel,

I once sat in the middle of a circle formed by twelve agitated members of the Scout Movement and argued with them about why I disagreed with their Scout Law (a sort of code of conduct).

You can't help but being assertive when you have a strong opinion and rhetoric bombs are being dropped all around you.

I think a practical solution to the lack of opportunities for deliberate practice is this: make yourself a reasonable, polarizing opinion about everything. Then make friends with opinions you don't agree with.

As friends, you'll interact with them more than you interact with strangers.

And equally important, when conversations do get heated (sometimes they do), you'll have an incentive not to jump into the top-left quadrant for an easy way out of the argument.