Players Blocking When They Are Second And Have The Last Move

I understand that a player (you) blocking during the game, but when you have the last move, why are you blocking your opponent who has no moves left?

I also understand how you can be so focused on your play that you sometimes don't look at your moves that you have left and how many moves your opponent have left. Today I have had at least five players where I am first and they have the last moves, block me with me having no moves left.

I try to pay attention to my moves, especially when I am first to know what I have as an option. Sometimes I too are caught up in the game and miss it. But when I am last, if so happen that my blocker fills up I look to make sure my opponent doesn't have any more moves and if not, it's just a filled blocker I can't use.

If you are the first player, on your last two moves if you have a blocker, use it. If you are the second player, if you want to block your opponent, you will have to do it when you have four moves left.

Two of those players this morning have had the clock run out on them just because they are looking to see where they can block.

Have you noticed this? Does this have an affect to your play or your opponent's play?