Well, hiking in mountains is surely something you have to take serious. Your safety and well-being depends on you. But to hike a long distance it takes exactly the same skills (and equipment…) as hiking for a week. Plus some logistics and time. The rest is about psychology and priorities.
My hiking experience before I started was apart from day hikes and occasional weekend hikes, limited to two longer hikes last summer. I also had been on two winter expeditions of each four days together with Friluftsfrämjandet.
My first long hike was a week on Hardangervidda together with three friends last summer in early July. We hiked 140 km, the weather was good but there was still a lot of snow left, which was challenging and required us to take decisions and considering our safety many times every day. It was certainly a good exercise in risk management, but it was never dangerous, because we had enough time, we could spend one hour to find a safe way to cross a river.
My second hike last summer was my first solohike and I spent 10 days in Padjelanta. No idea how far I hiked, I think somewhere around 150km. As it was my first solohike, I decided to plan with a lot of margins. Maybe I hate it? In that case it is good to be able to go home earlier. Maybe I love it? Well, in that case, it would be stupid to plan for only a few days. Maybe I hurt myself? Maybe the weather forces me to wait in my tent for a couple of days? So I ended up planning for 10 days on trail, with the only “fixed” points arrival in Ritsem Day 0 and flying out from Stáloluokta Day 10, that means a distance of around 60 km.
“Fixed”? Well, in terms of safety, there is no fixed appointment. The helicopter will fly without you, the train will not miss you if you don’t show up – and there are other trains to catch on other days. It is just not worth it to jeopardise your health just because you have booked your trip home. Or a work meeting. Or your own wedding.
So yes, my hiking experience was not extensive, in total some 30 nights in a tent (after the age of 15), and 2 hikes of at least a week. But I knew how to handle my gear even in strong wind and heavy rain, I knew I loved solohiking, I have common sense (the Swedish expression “sunt förnuft” is better suitable…), respect for the power of nature and all the time in the world…
With that being said: you need knowledge to understand what is dangerous, and what is not. So please prepare yourself for your hike. The Mountain Safety Council of Sweden/ Fjällsäkerhetsrådet has a lot of great material regarding this matter.
Hiking long distances can be hard, and you will most probably experience some pain, somewhere, sometime. But if you can hike for one week without major pain or getting too tired, the trick is to rest a day (or two), resupply food and then go out for another week. But you have to make it in your pace, listen to your body and make it your hike. It really is not more difficult than that. Physically at least. Psychologically, there are hundreds of challenges to overcome, but that is part of the beauty and addictiveness of long distance hiking.