That one day they will harvest my brain and let it live a vat of dopamine

Excited and scared for quantum computing

Fusion? That would be big. The continual role out of green energy which can push the price down. The McRib coming back. Normal things.

The steady improvement in computer speed and efficiency (unfortunately brought down by bloated software, but in some areas you feel it in absolute terms), storage and memory size, and EV technology. I hope in 2040 there will be cheap powerful e-scooters and e-motorcycles.

Quantum safe cryptography ciphers already exist

Differentiable programming. Differentiable ray tracers for example can be used to reconstruct the geometry of something you took a picture off.

I have a few.

Nuclear power reactors built after the 1970's. New generation (5?, 6?) for baseload. Mox, msr, lead moderated... Renewables can bicker over the transient loads while reactors provide the 'always on, always needed' bulk of power load.

Fuel reprocessing to close the loop would be the grail at this point.

Turbomuffins

JWST and what's coming next

Regenerative agriculture

It's very far thou, like 2040 type of boom technology