I have just re-logged on an old(er) Ubuntu today to perform 'With linux only possible tasks'.
I had been using that machine for more than a year. After that I had a new one so I don't use it so much now.
What strikes me : the desktop is not optimized to my work anymore.
With time we switch tools, we visit other websites... So if I wanted to use again that machine and be productive I should spend half a day upgrading applications here and there, getting new bookmarks...
Even if you do a lot in the cloud, you want to manipulate your cloud services with toolbars and other small clients.
I realize how much time I spend in keeping our laptops up to date... It's much more than we think.