If you are relocating, be careful with shipping. Make sure that, in both directions, you use a proper relocation company. They will know the right type of forms to use, to prevent you from paying duties on personal items you're simply taking with you back and forth.
I moved from the EU to Canada and back to the EU after about 1½ year. I used a relocation company in both directions, to relocate my goods. In particular on the way back, there forms to fill, in particular on goods I had acquired in the past 6, 12, or 24 months (IIRC) in Canada. I think I had to declare that all other goods, I owned already before I moved to Canada. For my computer, I could have provided evidence, but they didn't ask. If I had acquired goods while in Canada I would have had to pay import duties on them, depending on how recently I acquired them. I don't recall the details.
Someone I know moved from the EU to the USA and back to the EU after about 2½ years. She used a local parcel company to send her stuff back to the EU. Upon arrival, she was charged with significant import duties, which he dutifully paid, even though it was mostly stuff she already owned before moving to the USA.