I wish you a wonderful Teacher's Day! I've received this card through email and I really liked the message in it. Simple and deep. No matter the problems we may face in our classes, we need to bear in mind that, if we're doing our best, something valuable will always be shared with our students.
Some classes will be great, others will make us feel bad; some students will love us, others would rather have classes with somebody else; some days we will really believe in our jobs, other days we will think about doing something else...
but, in the end, teaching is still a fantastic and rewarding experience.
Enjoy your day!