So often we are trapped in either the regret/ guilt/suffering of the past or the fear/worry/suffering of the future. How we expected things to be in the past and how we failed or how we expect things to be in the future and what we fear expecting to happen. Bouncing between the past and future like bouncing between hot sides in an oven. Suffering; expectations resisting reality.
Buddhists say that failing to get what we desire, our attachment to things, is suffering. Stoic/Marcus Aurelius said “If you are distressed by anything external, the pain is not due to the thing itself but to your own estimate of it” meaning suffering doesn’t happen to us, our own judgment and self create suffering. We should not hope for things to go as we desire, the past or the future expectations, but for the past and future to go exactly as they did and exactly how they will.
This is not to say we shouldn’t dream and strive for the best, on the contrary, this is to do our best in the things we can control and not suffer in the things we can’t