Even if the gift came six months ago or longer, it’s better to write the note than not. Apologize for being tardy, move on without further excuse, and express your feelings. The recipient will appreciate it and forgive your lateness on the spot. That’s even more true if the gift isn’t a tangible one: It can take years to fully realize the impact of a person on your life. Don’t let this stop you from expressing your gratitude. Make it part of your routine to consider if there is anyone to whom you owe a thank-you letter.