So, I had to look up the call of the skylark, we do not have them in my area 😄 and it is without a doubt, a very cheerful and upbeat chirp.

This really makes me ponder on the second haiku. I think Basho was experiencing such an immense amount of sadness, that it almost becomes compounded by happiness. It's similar to when you're depressed at a party, yet everyone around you is laughing and having fun, and you end up feeling even worse... I get the impression he was dealing with a lost love, or perhaps some heavy grief...

Thank you for sharing this, some very somber thoughts to reflect on...