Illusive is exactly right. Meditation is the *practice* of learning to tune your mind. You can't suck at it. You are just at a different stage of practicing which is fine. Every human gets distracted thoughts, and the practice of meditation helps us to learn how to let those drift away again.
There will always be times that we get sucked into our thoughts, and that's normal! When we realize we have been, then we smile gently at ourselves, praise ourselves for realizing it, and refocus on our breath and the bubbles.