That “massage brain” feeling is pretty common. After a massage, your body often shifts into a deeply relaxed state, your nervous system slows down, and you may feel a little sleepy, spacey, or less mentally sharp for a short time.
It’s basically your body saying, “We’re not in go-mode anymore.”
Give yourself a few minutes, drink some water, move slowly when you stand up, and let your body ease back into the rest of your day. Most people feel back to normal pretty quickly.