I must be an outlier, because it's always been the opposite for me.
I started on Mercurial and didn't use Git for years. The moment I switched to Git everything made so much more sense to me. Mercurial seemed like it did magic and wouldn't explain it to you. There were multiple kinds of branches, there were revision numbers, octopus merges were impossible to understand, the whole thing tried to act immutable but effective workflows included history editing for squashing and merging and amending and cherry-picking, which is anything but. Partial commits were a little bit of a mystery to me, and shelves seemed to be their own separate thing.
To me Git was simple in comparison. The working copy was the last state at the end of a long sequence of states. Patches were just the way you represented going from one state to another, rather than canonical, so you woujldn't resolve an octopus merge so much as you would get to your desired state and call it a day. Branches were labels to a particular state. Stashes were labels with an optimized workflow. Reflog was just a list of temporary-ish labels. New commits were built against the index, which you could add or remove to independently of file state. Branches were branches were branches, no matter where the repository was. Disconnecting from upstream was simply a matter of removing a remote.
I know it doesn't match up with other people, but I simply have never been able to see Mercurial as an example of a good tool /despite starting on it/. It's always been easier to use git at any level of complexity I need it depending on the problem I'm solving, whether it's saving code or rescuing a totally botched interactive rebase, merge, etc.