I've been working with computers and have had laptops for too many years but they were all provided by my employer. I didn't buy my first laptop until just before I retired. I thought I wanted a Cadillac so I bought a 17" Toshiba multimedia laptop. It's a nice laptop and I still use it when needed but I find the need less often.
On our last RV excursion I took both the big laptop and my netbook and I never fired up the big laptop. One big reason is that the netbook uses almost no power. We were on the road for six months and always boondocking with no hookups. I could compute all day with our solar charging the batteries and keeping things going. With the power guzzling big laptop I would have been limited to a few hours.
The small screen and keyboard size hasn't been a problem. Fortunately I don't have fat fingers, just normal sized. I just think small and the keyboard works fine. For heavy key pounding I use a USB keyboard. The screen is no problem as well. My eyes aren't perfect but I normally use the little computer with no problem. When I need a bigger screen I use our TV/monitor in the RV.
I use the computer a lot for word processing, programming and web development. My little netbook handles all these needs with ease. The small size has an added benefit of availability. I can carry my netbook in my fanny pack to use anywhere, anytime.
If you're thinking of buying a new computer perhaps thinking small is a big idea.