Anyone can easily verify that this account was created by @yabapmatt on any Hive block explorer and be assured that it is really my account.
Well, not really. One can easily go and check, that indeed @yabapmatt.sps was created by @yabapmatt, but that could be exploited if there's an account creation service where @yabapmatt account is account creator.
And then it was also upvoted... but still it could be upvote trail or other voting service.
So actually a proof good enough was a comment you wrote using @yabapmatt account.
Anyway, good to see you around posting :-)
Good luck!
His official account shared or reblogged(as they say) this post. That was all the proof I needed.