I have a MacBook Air 11', Early 2014 with a 1,4GHz CPU and 4Gb of RAM. I was running MacOS 10.12 without any issues, everything was fast and responsive.
Then I upgraded to MacOS 10.14, skipping MacOS 10.13. Since then, my MacBook became very slow and irresponsive. The round, colored spinning icon indicating that there is something going on is now almost omnipresent. On MacOS 10.12 I saw it rarely. Switching between apps was smooth before, now it's painful. The MacBook feels always hot, even with just the browser open. The battery burns through a lot faster.
Do I have a messed up system? If so, why didn't I have issues before upgrading to Mojave? Is there anything I can do about it?
Or is my MacBook simply too slow to run Mojave decently? Apple lists it among the devices supported by Mojave. I'm interested in the experience of other users of the same model.