Is the difference between adolescence and maturity a matter of learning how to keep your emotions and expectations in check? Realising that while you may hold some strong, time-tested opinions of your own, the vast world beyond may not share the same beliefs? Let's leave aside the vast world, not even friends and family necessarily share the same opinions. Rhetorical, so I've already answered the questions with a yes.
There are two sources of inspiration for this. The first is Brexit-- so many people riding on high horses, so many unwilling to consider views other than their own. The liberal lefts are relentlessly insulting, deriding and shaming those who voted for leave. Meanwhile the conservative rights (some) are childishly bullying immigrants in public. It's very easy, when reading posts on social media, to fix your mindset and pledge unyielding allegiance to one side. For young Singaporeans like me, it is often difficult to resist the lure of the liberal left. Because SG itself is pretty liberal in some ways. But  we need to realise that the reality is bigger than that. I believe some people voted leave because they truly believed in it, and made a well-informed choice. Let's leave aside those who now claim ignorance. Come on, don't insult the intelligence of roughly 50% of the voters. So anyway, I feel that while the remain stance is valid, some of them are trumpeting their views in a very childish and obstinate manner. There are often many appropriate answers to the same question.

Another source is, well, myself. Self-explanatory.

If you cling obstinately to an opinion, you would find many negative things and you would view the world in a very disagreeable light. And you would be very disagreeable yourself. But the reality is much more than that. So why not acknowledge it and go get a life. Easier said than done. But doable.