Try to remember your last one
Most people cannot name the cards, the question, or the date. Some can recall that it felt right at the time. That is a strange outcome for something you chose to do and found meaningful while doing it.
The usual explanation is that the reading was shallow. Occasionally true, mostly not. The more ordinary explanation is that nothing about the format was built for the thing to survive.
Reading is consumption, not practice
An online reading arrives finished. You scroll, you feel something, you reach the end. Structurally that is closer to reading an article than to keeping a practice, and articles are forgotten at a rate nobody finds surprising.
The moment that makes a reading stick is the one after it, when you say what you think it means and what you intend to do. Almost no tool asks for that moment, and almost nobody supplies it unprompted.
Nothing is written down, so nothing accumulates
One reading is an anecdote. Twelve readings are data. The interesting thing is never a single card; it is that the same card keeps arriving whenever you are avoiding a decision, and you cannot see that without a record.
If your readings are not stored, every one starts from zero. You are having the first reading of your life, repeatedly. That is a large part of why they blur.
The question was too big to act on
"What does my future hold" produces text you cannot do anything with, and text you cannot act on leaves no trace. "What am I avoiding about this decision" produces something you either act on or deliberately do not, and both are memorable.
Question quality predicts retention better than reading quality does. It is the cheapest thing to fix and the one people skip.
Three fixes, about two minutes
Write one sentence immediately after: what you think it was about. Not the card meanings, your reading of them. This is the whole of the practice and it takes twenty seconds.
Name one thing you will do differently, however small. A reading with no consequence is entertainment, which is a fine thing to want and a different thing.
Keep it somewhere you will actually return to. A notebook works. A tool that stores readings works. A closed browser tab does not.
What changes when readings persist
The individual reading matters less, which sounds like a loss and is not. What appears instead is the shape of a few months: the questions you keep asking, the ones that resolved, the card you flinch at.
That is the part people describe as tarot having helped them. It is almost never one reading. It is having kept them.