Is there a downside of being a flexible, optimistic person?

The downsides, as I see them, are

- People take your optimism and flexibility as naivety and a lack of backbone. Also see Why is enthusiasm often perceived as naivety?
– The perception that there’s always another chance may be healthy, but it isn’t always true. Finding out there is a finite amount of opportunities can be difficult.
– Your actions and attitude affect others around you. As you gather people closer to you, that you either don’t want to lose, or can’t afford to lose, your built up history and reputation become more important. That includes whether or not you are perceived to care about your failures and shortcomings.
– At some point, someone will be reliant on you. There may be flexibility from your perspective, but not theirs.

All that said, the questions I come back to are what are the alternatives? A life of cynacism and planned, optimized, rigor? Do I prefer that?

I always come back to optimism, because that alternative is no way that I want to live. It’s completely unnatural to me and probably to you.

Just work on a healthy balance and realize what others see in your outlook and actions.

In general, and from a personal point of view, it is good to be adaptable and flexible, as you point out. And that’s not “only” from a personal point of view: it’s good for cultures to be adaptive and resilient, too.

But there’s also a downside, both personally and over a larger culture. In the context of the current political environment (at least in the USA) I hesitate to mention it, but only because the metaphor is so generally hyperbolic and overblown in terms of the current occupant of the White House, but it’s relevant, so I will use it. “What do you do when Hitler comes to power?”

If your response is to “be optimistic, as it means I won’t have to listen to boring political speeches from his opponents – because there won’t be any”, and “I won’t have to waste my time deciding among alternative candidates for high office – because there won’t be any” and “it will make my life much simpler to be told what to do, and when” and so forth, then that would indicate that you are an idiot, soon to be a slave, and soon after that to be dead.

It’s good to be flexible “in things that don’t matter”, but deadly to be flexible in things that matter very much.

With that sort of attitude, you don’t really have a choice about being flexible. “It’s all for the best” is a handy cliche, but better to recognize and accept the truth.

The only downside that I can see is if your abundance of optimism leads you to getting into risky arrangements. There is a difference between thinking, “that wasn’t so bad” and thinking, “what could possibly go wrong?”.

It sounds like a great way to be for the most part! I wish I were more like that.

Like others have said, it might lure you into the idea that you never have to take action to correct something bad that is happening. It’s great that you can cope with whatever bad things arise, but sometimes it’s better to try to take action early on to prevent the bad thing in the first place.

One way I believe optimists are harmful is in environmentalism. For example the attitude “maybe global warming isn’t real / won’t be that bad” is being used as an excuse to not try to do anything to alleviate the human impact on the environment, which could really end up biting us in the ass some years down the road.

I am much of your mind, and I see nothing to be gained by a negative attitude. But some people just naturally have a shitty outlook on life. They’d whine and complain if you hanged them with a golden rope and it wasn’t 24 carrots. I’d rather be “naive” than be constantly miserable and testy.

There will be some situations where you’ll have to show your anger / unhappiness to others if they take you for granted. Otherwise they’ll stop considering your opinion as important as you’ll be happy in anyway they behave.

A downside? I think it is a gift!
You do need to be careful others don’t take advantage of your good nature.

If I’m with a group I really don’t care where we go to eat. Chinese? Sure, Italian? Perfect, Japanese? Yum, Family Diner? Yep. It just doesn’t matter to me. It’s all good, man (Saul Goodman). OTOH, the pickier eater of the group always has some preference so we just go along for the ride. I wonder if that makes us look weak. Hmmm.
Or does it mean we enjoy everything?! I prefer that answer.