Almost everyone who stops meditating gives some version of the same reason. I could not stop thinking. It is offered as proof of being unusually bad at it.
It proves nothing. Minds produce thoughts continuously, and sitting quietly does not switch that off. It makes it audible. A person who sits down and discovers a great deal of mental noise has found what everybody finds, usually for the first time, because normally there is enough going on to cover it.
The loop is the practice
Here is the shape, and it repeats.
Attention is on the breath. Then attention is somewhere else, on a conversation from Tuesday, and has been for a while. Then you notice. Then it comes back.
In most descriptions of the practice, that noticing is the whole event. A stretch of unawareness ends. The breath was never the point; it is a fixed thing to depart from and return to, so that departures become detectable.
Which means a sitting full of wandering is a sitting full of things to notice. A sitting with none would be one long blank.
The mind will wander. Coming back is the practice.
You do not have to catch it quickly
A common private worry is about the lag. The mind was gone for four minutes before you realised, and somebody better would have caught it in four seconds.
Nothing in the ordinary accounts of practice supports that. The gap is not scored. Noticing after four minutes is noticing. And the impulse to grade the lag is one more thought, arriving dressed as self-improvement.
Nor is there any need to count. Some techniques count breaths deliberately, as an anchor, but nobody counts distractions. A tally is a project.
How to come back
Plainly, without the ceremony.
The usual instruction is to return attention to wherever it was resting, with as little commentary as possible. Not to review where it went, not to work out why, not to apologise to anyone. Notice, return, continue.
If naming it helps, a quiet thinking, or planning, or remembering, that is a real technique with a long history in the insight traditions, where it is called noting. It suits some people and irritates others. Either finding is fine.
The one thing widely described as unhelpful is making the return a correction. Coming back irritably is still coming back, and it adds a second thing to the sitting that was not there before.
The thought that will not leave
Sometimes there is one particular thing. An argument being rehearsed, a decision being turned over, a piece of unfinished business reappearing thirty seconds after each return.
Traditions offer different attitudes here, and their disagreement is the useful part, because it means there is no single right handling.
Name it and return anyway. Acknowledge it quietly and go back to the anchor, without requiring the thought to be resolved first. It may come back ten more times. That is allowed.
Let it be present. Some instructions suggest giving attention to the breath alongside the thought instead of in place of it. The thought stays in the room and you stop wrestling it.
Change what you are resting on. Switching the anchor outward, to sound in the room or the feet on the floor, is the common move when a thought has become sticky.
If one of these does nothing for you, the others exist. And if the thought is urgent, something you will forget and regret forgetting, write it down and sit afterwards.
If a sitting becomes distressing rather than merely busy, the answer is not a technique. Open your eyes, feel the floor, and stop. Sitting alone with difficult material is not something a timer can do for you, and nothing here is asking you to.
Why it feels worse than it is
There are two quiet reasons an ordinary wandering mind feels like a personal failing.
You only ever see your own. Everybody else's sitting is silent and outwardly composed. There is no way to observe that the person across the room spent eleven minutes on a work email, so the only inner experience available for comparison is the messiest one you have access to.
The noticing is what makes it visible. The usual account is that the wandering was always happening and sitting quietly only gives you a way to catch it. Which would explain why the first weeks can feel like the mind getting worse. Several traditions mention this specifically, presumably because it has been ending people's practice for a very long time.
Both are reasons the second week is often harder than the first.
What good looks like
There is no good. A sitting where attention rested easily and a sitting spent almost entirely in Tuesday's conversation are both sittings, and the second is simply what happened that day.
Neither one is a better use of twenty minutes than the other.