An imaginary door is limited less by its hinges than by what you can imagine on the other side.

The door is never the limit; the imagination of what lies beyond it is. Possibility is bounded by what you can picture, and if you cannot picture the other side, the fact that the door opens makes no difference. Most constraints are on the conceiving rather than on the doing.

So widen the picture before you decide what is possible. Talk to someone who has done the thing you cannot imagine, read about lives unlike yours, ask what you would try if the outcome were guaranteed. The point is not optimism but inventory: you cannot choose an option you have never managed to think of.