Buying clothes for baby’s first year...

I’ve had fun at sales so far and I’ve amassed a collection of clearance clothes through 6 months. However, everyone I seem to know says my baby will outgrow everything immediately.

How true is this really? I bought shorts and cute onesies with sea turtles on them and tank top onesies etc for 0-3 and 3-6 months for my end of March baby, for the warm months. Should I be worried that he will not even get to wear these things? What if he outgrows then in April and I have to go out and buy 6-9 month summer clothes?

But then you go on websites with lists of stuff you should buy for baby and it’s like...5 sleepers 8 onesies 5 pants 2 sweaters etc for EACH size which I haven’t done either. Why would I buy all these sleepers for summer months? What if I buy sweaters for 9 months just for him to outgrow it in August?

Should I buy more clothes in different seasons to cover my bases, or should I just not buy any more and figure it out when he’s here?