I am having a problem with my imagination since a year or two. I usually get absent minded during a lecture. I am good at studies and I know I can do better if I concentrate. I endure a feeling of heaviness over my brain sometimes. Even when solving an exam I commit silly mistakes just because my brain isn't quick to grasp the concept and even if it does it picks out the other. I'm also having a problem of looking at the mirror for a long time, my grandma says that my brain is two-way. What to do??
It seems that you need more energy as well as more focus. Fortunately, there are practices that can help you.
I think that the best place to begin is with Paramhansa Yogananda’s Energization Exercises. Here is a link to some information about this system and 3 of its exercises. Next time you go into a situation where your brain sometimes disappoints you, try those 3 sample exercises immediately beforehand. (It would be even better to do all 39 of those exercises; I am simply trying to give you a taste of it.)
If you find yourself getting off track at a time when you cannot do those 3 exercises – for example, in a classroom situation – do just the second exercise (quietly, perhaps sitting). It’s very effective.
Another valuable aid is the Full Yogic Breath: As you inhale through the nose, feel the belly expanding, then the lower ribs, and finally the chest. It’s as though you were pouring water into a bucket, but you’re pouring air into your lungs. As you exhale through the nose, first relax the chest, then the lower ribs, and finally the belly. It’s a strengthening way to breathe when you need a boost to your level of energy and your mental clarity. You can do it anytime you need a boost – but don’t do it all the time.
I hope these thoughts are helpful. As for looking in the mirror, I am unclear as to whether your problem is that you do it for too long, or that you’re not able to do it for as long as you would like. In either case, I don’t see any benefit in staring at yourself in a mirror. Far better to spend your time energizing and/or meditating so you can meet your true Self.