Three minutes’ thought would suffice to find this out, but thought is irksome and three minutes is a long time.
But for all Housman was having a go at someone, there is a truth in there: thought is irksome. Elsewhere in the house someone is struggling at an assignment in their MBA. And I have spent two hours writing poetry and have got maybe twelve lines, at least half of which I will change and the other half I may discard. That was irksome.
I wasted ten minutes on the internet researching bee pollination (researching, that makes it sound impressive: I typed bee pollination into google and got a wikipedia page with a table) because thought is irksome and poetry takes thought.
In fact, thought is so irksome I am going to pot up my tomato seedlings rather than do it any longer.