yes this is normal, and not a sign of him getting mad or having a tantrum either. He is 9 months old, why on earth would you be concerned with stopping anything that he feels or trys to do? getting mad is normal everyone does it, why do you want to try to control a 9 month old?
listen when i had my first child i beat myself up trying to live up to what everyone else said was normal, what some expert said my kid should be doing at this age, or if my kid did this or that it could be a sign of some horrible mental illness. The result? I drove myself crazy, needed cousiling, had a nervous high strung kid who at the age of 20 is still high strung and trying to fit in with people who arent fit for her to wipe her feet on.
so when baby #2 came along 15 years later, i said no way, i will not control, i will allow, she will be allowed to feel whatever it is she is feeling, so will I, i let her take the lead and took clues from her as to when she was ready to do certian things,{ hold a cup, brush teeth, potty train, etc} fist and formost yourson is a baby. will be a baby for years. ther are some people who will say that at age 2 they are not babys, but when you think about it they are. even at 3 they are, toddler to me begins almost at age 4. if your not a baby then you should be out getting a job or something, that usuallt shuts people up.
but anyhow, when i decided to let baby #2 be herself and not try to control her, and forget what other people say, she develpoed mentally so quickly, much more so than other kids her age. her behavior morriors that of an 7 year old instaed of a 4 year old, she could say 90 words by 1 year. talking in complete sentances by 16 months, potty trained herself with liitle help from me. if she got mad or frustrated about anything when she got older{not at 9 months} i would find out why and work through it with her. its all normal.
and when you quit trying to control your baby, and yourself, and let your self enjoy your life and your children you will be much happier. both of you. the experts are still going on stuff our parents learned, and our parents were never taught that children were to be loved, and gifts given to us by god. they were under the mental and social stigma that states that you get married, you have kids,a mortage,bills, my life sucks, etc,,,,burdens, is what children were to our parents and to their parents, not saying that they didnt love us, but its a learned behavior they learned from their parents, why else would a 8 and 10 year old be allowed to stay home and watch themselves while parents went to church or whatever?
love your son and EVERTHING he does, he will learn from you what good behavior is, and this not wanting to quit playing is normal. When your outside on a beautifull day, working in your garden or relaxing and reading and you look at the clock and see it is time to ready to go to work, dont you want to stay home and keep on enjoying the wonderfull day? why do you think your son should be any different. dont try to control. allow.