Yesterday my meditation was easy and today it was hard: My mind just kept drifting away to my weekend plans. What am I doing wrong?
First for the bad news: This is a very good description of doing the practice "correctly." Your question shows you now know some things about your own mind. You know that the mind you sat down to meditate with today was very different than the mind you sat down with yesterday. You know what "today's mind" was intent on doing: planning for the weekend. And you know your mind is quite happy to go ahead and do what it intends to do without asking for "your" permission! Great! The good news is that you also recognized at some point that the mind had "drifted away." The practice is to use that recognition to gently redirect the attention back to our intended focus. Some days our mind will throw a lot at us and we get a lot of practice redirecting; others, our mind will be settled and content to sustain attention on whatever we intend. Either way, our practice is to be with whatever our experience is, with as much self-compassion and curiosity as is available to us.