Time is a precious thing. Time can be your worst enemy or your best friend. It can be the "worst time of your life" or "the best time ever." Either way, time is important and changes you. It shows you your past, present and future. This is why it is OK to be selfish about your time and the people you spend it with.
Sure, we all have to go out on dates (that may end up awkward or may end up the best time ever), we have to meet that friend we haven't seen in a while, and other things. But as we get older, we see who is really important in our lives, and who has stayed in our lives through the tough stuff. Spend your time with people who want to spend their time with you. Don't waste your time with temporary people.
Not saying that hanging out with the new guy or girl you're seeing isn't important; it is. But if they have established that they don't want a long-term relationship or uttered things about how they "just aren't ready for anyone new," probably don't put in as much effort with them. Unfortunately, these people might not be easy to spot. They might be the person you thought you would spend a great deal of your time with. This is OK. It is OK to make mistakes with people and learn from them. Just try to spend your time with people who want to spend their time with you. If they are making the effort to be with you, you should hold on to that person.
It is OK to be selfish with your time. It's OK not to pretend that you enjoy someone's company when you simply don't. Don't go out with that person again. Time is a precious thing. Waste your time with a person you enjoy being around.